diff --git a/mypyc/test-data/exceptions.test b/mypyc/test-data/exceptions.test
index 28dabde9cd1c8..18983b2c92e94 100644
--- a/mypyc/test-data/exceptions.test
+++ b/mypyc/test-data/exceptions.test
@@ -176,7 +176,7 @@ L1:
     r2 = CPyObject_GetAttr(r0, r1)
     if is_error(r2) goto L3 (error at g:3) else goto L2
 L2:
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     dec_ref r2
     if is_error(r3) goto L3 (error at g:3) else goto L10
 L3:
@@ -189,7 +189,7 @@ L3:
 L4:
     r9 = [r5]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(r8, r10, 1, 0)
+    r11 = PyObject_Vectorcall(r8, r10, 1, 0)
     dec_ref r8
     if is_error(r11) goto L6 (error at g:5) else goto L11
 L5:
@@ -247,7 +247,7 @@ L1:
     r2 = CPyObject_GetAttr(r0, r1)
     if is_error(r2) goto L5 (error at a:3) else goto L2
 L2:
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     dec_ref r2
     if is_error(r3) goto L5 (error at a:3) else goto L19
 L3:
@@ -272,7 +272,7 @@ L6:
 L7:
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     dec_ref r13
     if is_error(r16) goto L20 (error at a:6) else goto L21
 L8:
@@ -491,7 +491,7 @@ L6:
 L7:
     r9 = [v]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(r7, r10, 1, 0)
+    r11 = PyObject_Vectorcall(r7, r10, 1, 0)
     dec_ref r7
     if is_error(r11) goto L15 (error at f:7) else goto L17
 L8:
diff --git a/mypyc/test-data/irbuild-basic.test b/mypyc/test-data/irbuild-basic.test
index 4067c2bf248db..075e6386663b1 100644
--- a/mypyc/test-data/irbuild-basic.test
+++ b/mypyc/test-data/irbuild-basic.test
@@ -496,7 +496,7 @@ L0:
     r3 = box(int, x)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = unbox(int, r6)
     return r7
@@ -587,7 +587,7 @@ L2:
     r33 = single :: module
     r34 = 'hello'
     r35 = CPyObject_GetAttr(r33, r34)
-    r36 = _PyObject_Vectorcall(r35, 0, 0, 0)
+    r36 = PyObject_Vectorcall(r35, 0, 0, 0)
     return 1
 
 [case testFromImport_toplevel]
@@ -626,19 +626,19 @@ L0:
     r3 = box(int, x)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = unbox(int, r6)
     r8 = __main__.globals :: static
     r9 = 'h'
     r10 = CPyDict_GetItem(r8, r9)
-    r11 = _PyObject_Vectorcall(r10, 0, 0, 0)
+    r11 = PyObject_Vectorcall(r10, 0, 0, 0)
     r12 = unbox(int, r11)
     r13 = CPyTagged_Add(r7, r12)
     r14 = __main__.globals :: static
     r15 = 'two'
     r16 = CPyDict_GetItem(r14, r15)
-    r17 = _PyObject_Vectorcall(r16, 0, 0, 0)
+    r17 = PyObject_Vectorcall(r16, 0, 0, 0)
     r18 = unbox(int, r17)
     r19 = CPyTagged_Add(r13, r18)
     return r19
@@ -696,7 +696,7 @@ L0:
     r3 = object 5
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     return 1
 
@@ -720,7 +720,7 @@ L0:
     r3 = object 5
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     return 1
 
@@ -1141,7 +1141,7 @@ L0:
     r3 = box(int, x)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = unbox(int, r6)
     return r7
@@ -1163,7 +1163,7 @@ def call_callable_type():
 L0:
     r0 = return_callable_type()
     f = r0
-    r1 = _PyObject_Vectorcall(f, 0, 0, 0)
+    r1 = PyObject_Vectorcall(f, 0, 0, 0)
     r2 = unbox(float, r1)
     return r2
 
@@ -1192,7 +1192,7 @@ L0:
     r2 = [x, r1]
     r3 = load_address r2
     r4 = ('base',)
-    r5 = _PyObject_Vectorcall(r0, r3, 1, r4)
+    r5 = PyObject_Vectorcall(r0, r3, 1, r4)
     keep_alive x, r1
     r6 = unbox(int, r5)
     return r6
@@ -1217,7 +1217,7 @@ L0:
     r4 = [r2, r3]
     r5 = load_address r4
     r6 = ('x',)
-    r7 = _PyObject_Vectorcall(r1, r5, 1, r6)
+    r7 = PyObject_Vectorcall(r1, r5, 1, r6)
     keep_alive r2, r3
     r8 = 'insert'
     r9 = CPyObject_GetAttr(xs, r8)
@@ -1226,7 +1226,7 @@ L0:
     r12 = [r10, r11]
     r13 = load_address r12
     r14 = ('x', 'i')
-    r15 = _PyObject_Vectorcall(r9, r13, 0, r14)
+    r15 = PyObject_Vectorcall(r9, r13, 0, r14)
     keep_alive r10, r11
     return xs
 
@@ -1393,7 +1393,7 @@ L0:
     r0 = builtins :: module
     r1 = 'Exception'
     r2 = CPyObject_GetAttr(r0, r1)
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     CPy_Raise(r3)
     unreachable
 def bar():
@@ -1436,7 +1436,7 @@ L0:
     r7 = box(int, r3)
     r8 = [r7]
     r9 = load_address r8
-    r10 = _PyObject_Vectorcall(r6, r9, 1, 0)
+    r10 = PyObject_Vectorcall(r6, r9, 1, 0)
     keep_alive r7
     return 1
 def __top_level__():
@@ -1484,7 +1484,7 @@ L2:
     r17 = box(int, r13)
     r18 = [r17]
     r19 = load_address r18
-    r20 = _PyObject_Vectorcall(r16, r19, 1, 0)
+    r20 = PyObject_Vectorcall(r16, r19, 1, 0)
     keep_alive r17
     return 1
 
@@ -1514,7 +1514,7 @@ L0:
     r3 = object 1
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = cast(str, r6)
     return r7
@@ -2269,7 +2269,7 @@ L2:
     r22 = CPyDict_GetItem(r20, r21)
     r23 = [r9, r19]
     r24 = load_address r23
-    r25 = _PyObject_Vectorcall(r22, r24, 2, 0)
+    r25 = PyObject_Vectorcall(r22, r24, 2, 0)
     keep_alive r9, r19
     r26 = __main__.globals :: static
     r27 = 'Lol'
@@ -2282,7 +2282,7 @@ L2:
     r34 = object 1
     r35 = [r34, r30]
     r36 = load_address r35
-    r37 = _PyObject_Vectorcall(r33, r36, 2, 0)
+    r37 = PyObject_Vectorcall(r33, r36, 2, 0)
     keep_alive r34, r30
     r38 = cast(tuple, r37)
     r39 = __main__.globals :: static
@@ -2307,7 +2307,7 @@ L2:
     r58 = CPyDict_GetItem(r56, r57)
     r59 = [r52, r55]
     r60 = load_address r59
-    r61 = _PyObject_Vectorcall(r58, r60, 2, 0)
+    r61 = PyObject_Vectorcall(r58, r60, 2, 0)
     keep_alive r52, r55
     r62 = __main__.globals :: static
     r63 = 'Bar'
@@ -2458,17 +2458,17 @@ L0:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     r8 = r0.f
-    r9 = _PyObject_Vectorcall(r8, 0, 0, 0)
+    r9 = PyObject_Vectorcall(r8, 0, 0, 0)
     r10 = 'Exited'
     r11 = builtins :: module
     r12 = 'print'
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     return 1
 def a(f):
@@ -2523,17 +2523,17 @@ L0:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     r8 = r0.f
-    r9 = _PyObject_Vectorcall(r8, 0, 0, 0)
+    r9 = PyObject_Vectorcall(r8, 0, 0, 0)
     r10 = '---'
     r11 = builtins :: module
     r12 = 'print'
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     return 1
 def b(f):
@@ -2581,7 +2581,7 @@ L0:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     return 1
 def c():
@@ -2620,14 +2620,14 @@ L0:
     r5 = CPyDict_GetItem(r3, r4)
     r6 = [r1]
     r7 = load_address r6
-    r8 = _PyObject_Vectorcall(r5, r7, 1, 0)
+    r8 = PyObject_Vectorcall(r5, r7, 1, 0)
     keep_alive r1
     r9 = __main__.globals :: static
     r10 = 'a'
     r11 = CPyDict_GetItem(r9, r10)
     r12 = [r8]
     r13 = load_address r12
-    r14 = _PyObject_Vectorcall(r11, r13, 1, 0)
+    r14 = PyObject_Vectorcall(r11, r13, 1, 0)
     keep_alive r8
     d = r14
     r15 = __main__.globals :: static
@@ -2640,9 +2640,9 @@ L0:
     r22 = CPyObject_GetAttr(r20, r21)
     r23 = [r19]
     r24 = load_address r23
-    r25 = _PyObject_Vectorcall(r22, r24, 1, 0)
+    r25 = PyObject_Vectorcall(r22, r24, 1, 0)
     keep_alive r19
-    r26 = _PyObject_Vectorcall(d, 0, 0, 0)
+    r26 = PyObject_Vectorcall(d, 0, 0, 0)
     return 1
 def __top_level__():
     r0, r1 :: object
@@ -2694,14 +2694,14 @@ L2:
     r14 = CPyDict_GetItem(r12, r13)
     r15 = [r11]
     r16 = load_address r15
-    r17 = _PyObject_Vectorcall(r14, r16, 1, 0)
+    r17 = PyObject_Vectorcall(r14, r16, 1, 0)
     keep_alive r11
     r18 = __main__.globals :: static
     r19 = 'a'
     r20 = CPyDict_GetItem(r18, r19)
     r21 = [r17]
     r22 = load_address r21
-    r23 = _PyObject_Vectorcall(r20, r22, 1, 0)
+    r23 = PyObject_Vectorcall(r20, r22, 1, 0)
     keep_alive r17
     r24 = __main__.globals :: static
     r25 = 'c'
@@ -2758,17 +2758,17 @@ L0:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     r8 = r0.f
-    r9 = _PyObject_Vectorcall(r8, 0, 0, 0)
+    r9 = PyObject_Vectorcall(r8, 0, 0, 0)
     r10 = 'Exited'
     r11 = builtins :: module
     r12 = 'print'
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     return 1
 def a(f):
@@ -2909,7 +2909,7 @@ L2:
     r4 = box(int, x)
     r5 = [r4]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(comparison, r6, 1, 0)
+    r7 = PyObject_Vectorcall(comparison, r6, 1, 0)
     keep_alive r4
     r8 = unbox(bool, r7)
     r9 = r8 << 1
@@ -3210,7 +3210,7 @@ L0:
     r3 = box(int, x)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     return 1
 
@@ -3435,7 +3435,7 @@ L0:
     r3 = object 2
     r4 = [r1, r2, r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r0, r5, 3, 0)
+    r6 = PyObject_Vectorcall(r0, r5, 3, 0)
     keep_alive r1, r2, r3
     r7 = cast(range, r6)
     r = r7
diff --git a/mypyc/test-data/irbuild-bytes.test b/mypyc/test-data/irbuild-bytes.test
index 7d1aee258080d..476c5ac59f48b 100644
--- a/mypyc/test-data/irbuild-bytes.test
+++ b/mypyc/test-data/irbuild-bytes.test
@@ -20,14 +20,14 @@ def f(num, l, d, s):
     r8, b2, r9, b3, r10, b4, r11, b5 :: bytes
 L0:
     r0 = load_address PyBytes_Type
-    r1 = _PyObject_Vectorcall(r0, 0, 0, 0)
+    r1 = PyObject_Vectorcall(r0, 0, 0, 0)
     r2 = cast(bytes, r1)
     b1 = r2
     r3 = load_address PyBytes_Type
     r4 = box(int, num)
     r5 = [r4]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r3, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r3, r6, 1, 0)
     keep_alive r4
     r8 = cast(bytes, r7)
     b2 = r8
@@ -59,7 +59,7 @@ L0:
     r0 = builtins :: module
     r1 = 'bytearray'
     r2 = CPyObject_GetAttr(r0, r1)
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     a = r3
     r4 = PyByteArray_FromObject(s)
     b = r4
diff --git a/mypyc/test-data/irbuild-classes.test b/mypyc/test-data/irbuild-classes.test
index b433ae5fd9a5d..2364b508aad93 100644
--- a/mypyc/test-data/irbuild-classes.test
+++ b/mypyc/test-data/irbuild-classes.test
@@ -285,7 +285,7 @@ L2:
     r16 = CPyDict_GetItem(r14, r15)
     r17 = [r13]
     r18 = load_address r17
-    r19 = _PyObject_Vectorcall(r16, r18, 1, 0)
+    r19 = PyObject_Vectorcall(r16, r18, 1, 0)
     keep_alive r13
     r20 = __main__.globals :: static
     r21 = 'T'
@@ -766,11 +766,11 @@ L0:
     r3 = __main__.DictSubclass :: type
     r4 = [r3, self]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 2, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 2, 0)
     keep_alive r3, self
     r7 = '__init__'
     r8 = CPyObject_GetAttr(r6, r7)
-    r9 = _PyObject_Vectorcall(r8, 0, 0, 0)
+    r9 = PyObject_Vectorcall(r8, 0, 0, 0)
     return 1
 
 [case testClassVariable]
diff --git a/mypyc/test-data/irbuild-dict.test b/mypyc/test-data/irbuild-dict.test
index fd56163d73791..258bf953b09c8 100644
--- a/mypyc/test-data/irbuild-dict.test
+++ b/mypyc/test-data/irbuild-dict.test
@@ -373,7 +373,7 @@ L2:
     r12 = load_address PyLong_Type
     r13 = [v]
     r14 = load_address r13
-    r15 = _PyObject_Vectorcall(r12, r14, 1, 0)
+    r15 = PyObject_Vectorcall(r12, r14, 1, 0)
     keep_alive v
     r16 = unbox(int, r15)
     r17 = box(int, r16)
diff --git a/mypyc/test-data/irbuild-glue-methods.test b/mypyc/test-data/irbuild-glue-methods.test
index f33942a4f3d95..35e6be1283ebb 100644
--- a/mypyc/test-data/irbuild-glue-methods.test
+++ b/mypyc/test-data/irbuild-glue-methods.test
@@ -207,7 +207,7 @@ L0:
     r3 = box(int, r1)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = unbox(int, r6)
     r8 = DerivedProperty(r0, r7)
@@ -248,14 +248,14 @@ L0:
     r3 = box(int, r1)
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r2, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r2, r5, 1, 0)
     keep_alive r3
     r7 = unbox(int, r6)
     r8 = self._incr_func
     r9 = box(int, r7)
     r10 = [r9]
     r11 = load_address r10
-    r12 = _PyObject_Vectorcall(r8, r11, 1, 0)
+    r12 = PyObject_Vectorcall(r8, r11, 1, 0)
     keep_alive r9
     r13 = unbox(int, r12)
     r14 = AgainProperty(r0, r13)
diff --git a/mypyc/test-data/irbuild-match.test b/mypyc/test-data/irbuild-match.test
index bd8878c5009e1..c5dc81bbf049e 100644
--- a/mypyc/test-data/irbuild-match.test
+++ b/mypyc/test-data/irbuild-match.test
@@ -23,7 +23,7 @@ L1:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     goto L3
 L2:
@@ -61,7 +61,7 @@ L3:
     r5 = CPyObject_GetAttr(r3, r4)
     r6 = [r2]
     r7 = load_address r6
-    r8 = _PyObject_Vectorcall(r5, r7, 1, 0)
+    r8 = PyObject_Vectorcall(r5, r7, 1, 0)
     keep_alive r2
     goto L5
 L4:
@@ -105,7 +105,7 @@ L5:
     r7 = CPyObject_GetAttr(r5, r6)
     r8 = [r4]
     r9 = load_address r8
-    r10 = _PyObject_Vectorcall(r7, r9, 1, 0)
+    r10 = PyObject_Vectorcall(r7, r9, 1, 0)
     keep_alive r4
     goto L7
 L6:
@@ -141,7 +141,7 @@ L1:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [r3]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive r3
     goto L3
 L2:
@@ -170,7 +170,7 @@ L1:
     r3 = CPyObject_GetAttr(r1, r2)
     r4 = [r0]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r3, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r3, r5, 1, 0)
     keep_alive r0
     goto L3
 L2:
@@ -212,7 +212,7 @@ L1:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     goto L5
 L2:
@@ -225,7 +225,7 @@ L3:
     r12 = CPyObject_GetAttr(r10, r11)
     r13 = [r9]
     r14 = load_address r13
-    r15 = _PyObject_Vectorcall(r12, r14, 1, 0)
+    r15 = PyObject_Vectorcall(r12, r14, 1, 0)
     keep_alive r9
     goto L5
 L4:
@@ -278,7 +278,7 @@ L1:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     goto L9
 L2:
@@ -296,7 +296,7 @@ L5:
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     goto L9
 L6:
@@ -309,7 +309,7 @@ L7:
     r21 = CPyObject_GetAttr(r19, r20)
     r22 = [r18]
     r23 = load_address r22
-    r24 = _PyObject_Vectorcall(r21, r23, 1, 0)
+    r24 = PyObject_Vectorcall(r21, r23, 1, 0)
     keep_alive r18
     goto L9
 L8:
@@ -344,7 +344,7 @@ L2:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
     goto L4
 L3:
@@ -400,7 +400,7 @@ L1:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [r3]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive r3
     goto L7
 L2:
@@ -415,7 +415,7 @@ L3:
     r16 = CPyObject_GetAttr(r14, r15)
     r17 = [r13]
     r18 = load_address r17
-    r19 = _PyObject_Vectorcall(r16, r18, 1, 0)
+    r19 = PyObject_Vectorcall(r16, r18, 1, 0)
     keep_alive r13
     goto L7
 L4:
@@ -430,7 +430,7 @@ L5:
     r26 = CPyObject_GetAttr(r24, r25)
     r27 = [r23]
     r28 = load_address r27
-    r29 = _PyObject_Vectorcall(r26, r28, 1, 0)
+    r29 = PyObject_Vectorcall(r26, r28, 1, 0)
     keep_alive r23
     goto L7
 L6:
@@ -471,7 +471,7 @@ L3:
     r7 = CPyObject_GetAttr(r5, r6)
     r8 = [r4]
     r9 = load_address r8
-    r10 = _PyObject_Vectorcall(r7, r9, 1, 0)
+    r10 = PyObject_Vectorcall(r7, r9, 1, 0)
     keep_alive r4
     goto L5
 L4:
@@ -504,7 +504,7 @@ L1:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [x]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive x
     goto L3
 L2:
@@ -546,7 +546,7 @@ L3:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [x]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive x
     goto L5
 L4:
@@ -584,7 +584,7 @@ L2:
     r6 = box(int, i)
     r7 = [r6]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r5, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r5, r8, 1, 0)
     keep_alive r6
     goto L4
 L3:
@@ -682,7 +682,7 @@ L4:
     r28 = CPyObject_GetAttr(r26, r27)
     r29 = [r25]
     r30 = load_address r29
-    r31 = _PyObject_Vectorcall(r28, r30, 1, 0)
+    r31 = PyObject_Vectorcall(r28, r30, 1, 0)
     keep_alive r25
     goto L6
 L5:
@@ -767,7 +767,7 @@ L4:
     r28 = CPyObject_GetAttr(r26, r27)
     r29 = [r25]
     r30 = load_address r29
-    r31 = _PyObject_Vectorcall(r28, r30, 1, 0)
+    r31 = PyObject_Vectorcall(r28, r30, 1, 0)
     keep_alive r25
     goto L6
 L5:
@@ -835,7 +835,7 @@ L4:
     r19 = CPyObject_GetAttr(r17, r18)
     r20 = [r16]
     r21 = load_address r20
-    r22 = _PyObject_Vectorcall(r19, r21, 1, 0)
+    r22 = PyObject_Vectorcall(r19, r21, 1, 0)
     keep_alive r16
     goto L6
 L5:
@@ -920,7 +920,7 @@ L4:
     r22 = CPyObject_GetAttr(r20, r21)
     r23 = [r19]
     r24 = load_address r23
-    r25 = _PyObject_Vectorcall(r22, r24, 1, 0)
+    r25 = PyObject_Vectorcall(r22, r24, 1, 0)
     keep_alive r19
     goto L6
 L5:
@@ -980,7 +980,7 @@ L2:
     r10 = CPyObject_GetAttr(r8, r9)
     r11 = [r7]
     r12 = load_address r11
-    r13 = _PyObject_Vectorcall(r10, r12, 1, 0)
+    r13 = PyObject_Vectorcall(r10, r12, 1, 0)
     keep_alive r7
     goto L4
 L3:
@@ -1015,7 +1015,7 @@ L1:
     r5 = CPyObject_GetAttr(r3, r4)
     r6 = [r2]
     r7 = load_address r6
-    r8 = _PyObject_Vectorcall(r5, r7, 1, 0)
+    r8 = PyObject_Vectorcall(r5, r7, 1, 0)
     keep_alive r2
     goto L3
 L2:
@@ -1072,7 +1072,7 @@ L3:
     r14 = CPyObject_GetAttr(r12, r13)
     r15 = [r11]
     r16 = load_address r15
-    r17 = _PyObject_Vectorcall(r14, r16, 1, 0)
+    r17 = PyObject_Vectorcall(r14, r16, 1, 0)
     keep_alive r11
     goto L5
 L4:
@@ -1111,7 +1111,7 @@ L2:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [r3]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive r3
     goto L4
 L3:
@@ -1176,7 +1176,7 @@ L4:
     r17 = CPyObject_GetAttr(r15, r16)
     r18 = [r14]
     r19 = load_address r18
-    r20 = _PyObject_Vectorcall(r17, r19, 1, 0)
+    r20 = PyObject_Vectorcall(r17, r19, 1, 0)
     keep_alive r14
     goto L6
 L5:
@@ -1218,7 +1218,7 @@ L2:
     r8 = CPyObject_GetAttr(r6, r7)
     r9 = [r5]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(r8, r10, 1, 0)
+    r11 = PyObject_Vectorcall(r8, r10, 1, 0)
     keep_alive r5
     goto L4
 L3:
@@ -1284,7 +1284,7 @@ L4:
     r20 = CPyObject_GetAttr(r18, r19)
     r21 = [r17]
     r22 = load_address r21
-    r23 = _PyObject_Vectorcall(r20, r22, 1, 0)
+    r23 = PyObject_Vectorcall(r20, r22, 1, 0)
     keep_alive r17
     goto L6
 L5:
@@ -1350,7 +1350,7 @@ L4:
     r20 = CPyObject_GetAttr(r18, r19)
     r21 = [r17]
     r22 = load_address r21
-    r23 = _PyObject_Vectorcall(r20, r22, 1, 0)
+    r23 = PyObject_Vectorcall(r20, r22, 1, 0)
     keep_alive r17
     goto L6
 L5:
@@ -1424,7 +1424,7 @@ L5:
     r23 = CPyObject_GetAttr(r21, r22)
     r24 = [r20]
     r25 = load_address r24
-    r26 = _PyObject_Vectorcall(r23, r25, 1, 0)
+    r26 = PyObject_Vectorcall(r23, r25, 1, 0)
     keep_alive r20
     goto L7
 L6:
@@ -1505,7 +1505,7 @@ L5:
     r24 = CPyObject_GetAttr(r22, r23)
     r25 = [r21]
     r26 = load_address r25
-    r27 = _PyObject_Vectorcall(r24, r26, 1, 0)
+    r27 = PyObject_Vectorcall(r24, r26, 1, 0)
     keep_alive r21
     goto L7
 L6:
@@ -1584,7 +1584,7 @@ L5:
     r25 = CPyObject_GetAttr(r23, r24)
     r26 = [r22]
     r27 = load_address r26
-    r28 = _PyObject_Vectorcall(r25, r27, 1, 0)
+    r28 = PyObject_Vectorcall(r25, r27, 1, 0)
     keep_alive r22
     goto L7
 L6:
@@ -1623,7 +1623,7 @@ L2:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [r3]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive r3
     goto L4
 L3:
@@ -1673,7 +1673,7 @@ L3:
     r11 = CPyObject_GetAttr(r9, r10)
     r12 = [r8]
     r13 = load_address r12
-    r14 = _PyObject_Vectorcall(r11, r13, 1, 0)
+    r14 = PyObject_Vectorcall(r11, r13, 1, 0)
     keep_alive r8
     goto L5
 L4:
diff --git a/mypyc/test-data/irbuild-nested.test b/mypyc/test-data/irbuild-nested.test
index f65c101b737a8..1b390e9c35043 100644
--- a/mypyc/test-data/irbuild-nested.test
+++ b/mypyc/test-data/irbuild-nested.test
@@ -210,14 +210,14 @@ L0:
     r3 = 'one'
     r4 = [r3]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(inner, r5, 1, 0)
+    r6 = PyObject_Vectorcall(inner, r5, 1, 0)
     keep_alive r3
     r7 = cast(str, r6)
     a = r7
     r8 = 'two'
     r9 = [r8]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(inner, r10, 1, 0)
+    r11 = PyObject_Vectorcall(inner, r10, 1, 0)
     keep_alive r8
     r12 = cast(str, r11)
     b = r12
@@ -300,7 +300,7 @@ L0:
     r2 = inner_a_obj()
     r2.__mypyc_env__ = r0; r3 = is_error
     inner = r2
-    r4 = _PyObject_Vectorcall(inner, 0, 0, 0)
+    r4 = PyObject_Vectorcall(inner, 0, 0, 0)
     r5 = unbox(int, r4)
     return r5
 def inner_b_obj.__get__(__mypyc_self__, instance, owner):
@@ -340,7 +340,7 @@ L0:
     r2 = inner_b_obj()
     r2.__mypyc_env__ = r0; r3 = is_error
     inner = r2
-    r4 = _PyObject_Vectorcall(inner, 0, 0, 0)
+    r4 = PyObject_Vectorcall(inner, 0, 0, 0)
     r5 = unbox(int, r4)
     r6 = r0.num
     r7 = CPyTagged_Add(r5, r6)
@@ -410,7 +410,7 @@ L2:
     r3.__mypyc_env__ = r0; r4 = is_error
     inner = r3
 L3:
-    r5 = _PyObject_Vectorcall(inner, 0, 0, 0)
+    r5 = PyObject_Vectorcall(inner, 0, 0, 0)
     r6 = cast(str, r5)
     return r6
 
@@ -482,7 +482,7 @@ L0:
     r6 = c_a_b_obj()
     r6.__mypyc_env__ = r1; r7 = is_error
     c = r6
-    r8 = _PyObject_Vectorcall(c, 0, 0, 0)
+    r8 = PyObject_Vectorcall(c, 0, 0, 0)
     r9 = unbox(int, r8)
     return r9
 def a():
@@ -498,7 +498,7 @@ L0:
     r2 = b_a_obj()
     r2.__mypyc_env__ = r0; r3 = is_error
     b = r2
-    r4 = _PyObject_Vectorcall(b, 0, 0, 0)
+    r4 = PyObject_Vectorcall(b, 0, 0, 0)
     r5 = unbox(int, r4)
     return r5
 
@@ -577,7 +577,7 @@ L2:
     r3.__mypyc_env__ = r0; r4 = is_error
     inner = r3
 L3:
-    r5 = _PyObject_Vectorcall(inner, 0, 0, 0)
+    r5 = PyObject_Vectorcall(inner, 0, 0, 0)
     r6 = cast(str, r5)
     return r6
 
@@ -642,7 +642,7 @@ def bar_f_obj.__call__(__mypyc_self__):
 L0:
     r0 = __mypyc_self__.__mypyc_env__
     r1 = r0.foo
-    r2 = _PyObject_Vectorcall(r1, 0, 0, 0)
+    r2 = PyObject_Vectorcall(r1, 0, 0, 0)
     r3 = unbox(int, r2)
     return r3
 def baz_f_obj.__get__(__mypyc_self__, instance, owner):
@@ -681,7 +681,7 @@ L2:
     r4 = box(int, r2)
     r5 = [r4]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r3, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r3, r6, 1, 0)
     keep_alive r4
     r8 = unbox(int, r7)
     r9 = CPyTagged_Add(n, r8)
@@ -716,14 +716,14 @@ L0:
     r8.__mypyc_env__ = r0; r9 = is_error
     r0.baz = r8; r10 = is_error
     r11 = r0.bar
-    r12 = _PyObject_Vectorcall(r11, 0, 0, 0)
+    r12 = PyObject_Vectorcall(r11, 0, 0, 0)
     r13 = unbox(int, r12)
     r14 = r0.a
     r15 = r0.baz
     r16 = box(int, r14)
     r17 = [r16]
     r18 = load_address r17
-    r19 = _PyObject_Vectorcall(r15, r18, 1, 0)
+    r19 = PyObject_Vectorcall(r15, r18, 1, 0)
     keep_alive r16
     r20 = unbox(int, r19)
     r21 = CPyTagged_Add(r13, r20)
@@ -784,7 +784,7 @@ L0:
     r1 = r0.s
     r2 = [a, b]
     r3 = load_address r2
-    r4 = _PyObject_Vectorcall(r1, r3, 2, 0)
+    r4 = PyObject_Vectorcall(r1, r3, 2, 0)
     keep_alive a, b
     return r4
 def f(x, y):
@@ -811,7 +811,7 @@ L0:
     r7 = box(int, y)
     r8 = [r6, r7]
     r9 = load_address r8
-    r10 = _PyObject_Vectorcall(t, r9, 2, 0)
+    r10 = PyObject_Vectorcall(t, r9, 2, 0)
     keep_alive r6, r7
     r11 = unbox(None, r10)
     return r11
diff --git a/mypyc/test-data/irbuild-singledispatch.test b/mypyc/test-data/irbuild-singledispatch.test
index b00645de1112e..c95e832cc5dfa 100644
--- a/mypyc/test-data/irbuild-singledispatch.test
+++ b/mypyc/test-data/irbuild-singledispatch.test
@@ -74,7 +74,7 @@ L2:
     r10 = __mypyc_self__.registry
     r11 = [r1, r10]
     r12 = load_address r11
-    r13 = _PyObject_Vectorcall(r9, r12, 2, 0)
+    r13 = PyObject_Vectorcall(r9, r12, 2, 0)
     keep_alive r1, r10
     r14 = CPyDict_SetItem(r2, r1, r13)
     r15 = r14 >= 0 :: signed
@@ -99,7 +99,7 @@ L6:
 L7:
     r24 = [arg]
     r25 = load_address r24
-    r26 = _PyObject_Vectorcall(r6, r25, 1, 0)
+    r26 = PyObject_Vectorcall(r6, r25, 1, 0)
     keep_alive arg
     r27 = unbox(bool, r26)
     return r27
@@ -212,7 +212,7 @@ L2:
     r10 = __mypyc_self__.registry
     r11 = [r1, r10]
     r12 = load_address r11
-    r13 = _PyObject_Vectorcall(r9, r12, 2, 0)
+    r13 = PyObject_Vectorcall(r9, r12, 2, 0)
     keep_alive r1, r10
     r14 = CPyDict_SetItem(r2, r1, r13)
     r15 = r14 >= 0 :: signed
@@ -230,7 +230,7 @@ L4:
 L5:
     r21 = [x]
     r22 = load_address r21
-    r23 = _PyObject_Vectorcall(r6, r22, 1, 0)
+    r23 = PyObject_Vectorcall(r6, r22, 1, 0)
     keep_alive x
     r24 = unbox(None, r23)
     return r24
diff --git a/mypyc/test-data/irbuild-statements.test b/mypyc/test-data/irbuild-statements.test
index 98b04af12acd8..d5df984cfe4be 100644
--- a/mypyc/test-data/irbuild-statements.test
+++ b/mypyc/test-data/irbuild-statements.test
@@ -673,7 +673,7 @@ L2:
     r6 = CPyObject_GetAttr(r4, r5)
     r7 = [s]
     r8 = load_address r7
-    r9 = _PyObject_Vectorcall(r6, r8, 1, 0)
+    r9 = PyObject_Vectorcall(r6, r8, 1, 0)
     keep_alive s
     CPy_Raise(r9)
     unreachable
diff --git a/mypyc/test-data/irbuild-str.test b/mypyc/test-data/irbuild-str.test
index aadda1484fca0..35edc79f4ae5d 100644
--- a/mypyc/test-data/irbuild-str.test
+++ b/mypyc/test-data/irbuild-str.test
@@ -363,21 +363,21 @@ L0:
     r20 = [r17, errors]
     r21 = load_address r20
     r22 = ('errors',)
-    r23 = _PyObject_Vectorcall(r19, r21, 1, r22)
+    r23 = PyObject_Vectorcall(r19, r21, 1, r22)
     keep_alive r17, errors
     r24 = 'encode'
     r25 = CPyObject_GetAttr(s, r24)
     r26 = [errors]
     r27 = load_address r26
     r28 = ('errors',)
-    r29 = _PyObject_Vectorcall(r25, r27, 0, r28)
+    r29 = PyObject_Vectorcall(r25, r27, 0, r28)
     keep_alive errors
     r30 = 'encode'
     r31 = CPyObject_GetAttr(s, r30)
     r32 = [encoding, errors]
     r33 = load_address r32
     r34 = ('encoding', 'errors')
-    r35 = _PyObject_Vectorcall(r31, r33, 0, r34)
+    r35 = PyObject_Vectorcall(r31, r33, 0, r34)
     keep_alive encoding, errors
     r36 = 'latin2'
     r37 = CPy_Encode(s, r36, 0)
@@ -427,7 +427,7 @@ L0:
     r2 = CPyObject_GetAttr(r0, r1)
     r3 = [x]
     r4 = load_address r3
-    r5 = _PyObject_Vectorcall(r2, r4, 1, 0)
+    r5 = PyObject_Vectorcall(r2, r4, 1, 0)
     keep_alive x
     r6 = unbox(int, r5)
     return r6
diff --git a/mypyc/test-data/irbuild-try.test b/mypyc/test-data/irbuild-try.test
index 49a625e2d1b9d..ad1aa78c0554b 100644
--- a/mypyc/test-data/irbuild-try.test
+++ b/mypyc/test-data/irbuild-try.test
@@ -23,7 +23,7 @@ L1:
     r0 = builtins :: module
     r1 = 'object'
     r2 = CPyObject_GetAttr(r0, r1)
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     goto L5
 L2: (handler for L1)
     r4 = CPy_CatchError()
@@ -33,7 +33,7 @@ L2: (handler for L1)
     r8 = CPyObject_GetAttr(r6, r7)
     r9 = [r5]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(r8, r10, 1, 0)
+    r11 = PyObject_Vectorcall(r8, r10, 1, 0)
     keep_alive r5
 L3:
     CPy_RestoreExcInfo(r4)
@@ -77,7 +77,7 @@ L2:
     r0 = builtins :: module
     r1 = 'object'
     r2 = CPyObject_GetAttr(r0, r1)
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     goto L4
 L3:
     r4 = 'hi'
@@ -92,7 +92,7 @@ L5: (handler for L1, L2, L3, L4)
     r10 = CPyObject_GetAttr(r8, r9)
     r11 = [r7]
     r12 = load_address r11
-    r13 = _PyObject_Vectorcall(r10, r12, 1, 0)
+    r13 = PyObject_Vectorcall(r10, r12, 1, 0)
     keep_alive r7
 L6:
     CPy_RestoreExcInfo(r6)
@@ -156,13 +156,13 @@ L1:
     r3 = CPyObject_GetAttr(r1, r2)
     r4 = [r0]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r3, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r3, r5, 1, 0)
     keep_alive r0
 L2:
     r7 = builtins :: module
     r8 = 'object'
     r9 = CPyObject_GetAttr(r7, r8)
-    r10 = _PyObject_Vectorcall(r9, 0, 0, 0)
+    r10 = PyObject_Vectorcall(r9, 0, 0, 0)
     goto L8
 L3: (handler for L2)
     r11 = CPy_CatchError()
@@ -180,7 +180,7 @@ L4:
     r20 = CPyObject_GetAttr(r18, r19)
     r21 = [r17, e]
     r22 = load_address r21
-    r23 = _PyObject_Vectorcall(r20, r22, 2, 0)
+    r23 = PyObject_Vectorcall(r20, r22, 2, 0)
     keep_alive r17, e
     goto L6
 L5:
@@ -203,7 +203,7 @@ L9: (handler for L1, L6, L7, L8)
     r29 = CPyObject_GetAttr(r27, r28)
     r30 = [r26]
     r31 = load_address r30
-    r32 = _PyObject_Vectorcall(r29, r31, 1, 0)
+    r32 = PyObject_Vectorcall(r29, r31, 1, 0)
     keep_alive r26
 L10:
     CPy_RestoreExcInfo(r25)
@@ -265,7 +265,7 @@ L3:
     r8 = CPyObject_GetAttr(r6, r7)
     r9 = [r5]
     r10 = load_address r9
-    r11 = _PyObject_Vectorcall(r8, r10, 1, 0)
+    r11 = PyObject_Vectorcall(r8, r10, 1, 0)
     keep_alive r5
     goto L7
 L4:
@@ -281,7 +281,7 @@ L5:
     r19 = CPyObject_GetAttr(r17, r18)
     r20 = [r16]
     r21 = load_address r20
-    r22 = _PyObject_Vectorcall(r19, r21, 1, 0)
+    r22 = PyObject_Vectorcall(r19, r21, 1, 0)
     keep_alive r16
     goto L7
 L6:
@@ -333,7 +333,7 @@ L2:
     r3 = CPyObject_GetAttr(r1, r2)
     r4 = [r0]
     r5 = load_address r4
-    r6 = _PyObject_Vectorcall(r3, r5, 1, 0)
+    r6 = PyObject_Vectorcall(r3, r5, 1, 0)
     keep_alive r0
     CPy_Raise(r6)
     unreachable
@@ -353,7 +353,7 @@ L7:
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     if is_error(r8) goto L9 else goto L8
 L8:
@@ -411,7 +411,7 @@ def foo(x):
     r35 :: object
     r36 :: bit
 L0:
-    r0 = _PyObject_Vectorcall(x, 0, 0, 0)
+    r0 = PyObject_Vectorcall(x, 0, 0, 0)
     r1 = PyObject_Type(r0)
     r2 = '__exit__'
     r3 = CPyObject_GetAttr(r1, r2)
@@ -419,7 +419,7 @@ L0:
     r5 = CPyObject_GetAttr(r1, r4)
     r6 = [r0]
     r7 = load_address r6
-    r8 = _PyObject_Vectorcall(r5, r7, 1, 0)
+    r8 = PyObject_Vectorcall(r5, r7, 1, 0)
     keep_alive r0
     r9 = 1
 L1:
@@ -431,7 +431,7 @@ L2:
     r13 = CPyObject_GetAttr(r11, r12)
     r14 = [r10]
     r15 = load_address r14
-    r16 = _PyObject_Vectorcall(r13, r15, 1, 0)
+    r16 = PyObject_Vectorcall(r13, r15, 1, 0)
     keep_alive r10
     goto L8
 L3: (handler for L2)
@@ -443,7 +443,7 @@ L3: (handler for L2)
     r21 = r18[2]
     r22 = [r0, r19, r20, r21]
     r23 = load_address r22
-    r24 = _PyObject_Vectorcall(r3, r23, 4, 0)
+    r24 = PyObject_Vectorcall(r3, r23, 4, 0)
     keep_alive r0, r19, r20, r21
     r25 = PyObject_IsTrue(r24)
     r26 = r25 >= 0 :: signed
@@ -475,7 +475,7 @@ L13:
     r32 = load_address _Py_NoneStruct
     r33 = [r0, r32, r32, r32]
     r34 = load_address r33
-    r35 = _PyObject_Vectorcall(r3, r34, 4, 0)
+    r35 = PyObject_Vectorcall(r3, r34, 4, 0)
     keep_alive r0, r32, r32, r32
 L14:
     if is_error(r30) goto L16 else goto L15
@@ -548,7 +548,7 @@ L2:
     r5 = CPyObject_GetAttr(r3, r4)
     r6 = [r2]
     r7 = load_address r6
-    r8 = _PyObject_Vectorcall(r5, r7, 1, 0)
+    r8 = PyObject_Vectorcall(r5, r7, 1, 0)
     keep_alive r2
     goto L8
 L3: (handler for L2)
diff --git a/mypyc/test-data/irbuild-unreachable.test b/mypyc/test-data/irbuild-unreachable.test
index 895bf3b1dfeb5..7209c00ce75d8 100644
--- a/mypyc/test-data/irbuild-unreachable.test
+++ b/mypyc/test-data/irbuild-unreachable.test
@@ -205,7 +205,7 @@ L1:
     r0 = builtins :: module
     r1 = 'ValueError'
     r2 = CPyObject_GetAttr(r0, r1)
-    r3 = _PyObject_Vectorcall(r2, 0, 0, 0)
+    r3 = PyObject_Vectorcall(r2, 0, 0, 0)
     CPy_Raise(r3)
     unreachable
 L2:
@@ -241,7 +241,7 @@ L3:
     r4 = CPyObject_GetAttr(r2, r3)
     r5 = [r1]
     r6 = load_address r5
-    r7 = _PyObject_Vectorcall(r4, r6, 1, 0)
+    r7 = PyObject_Vectorcall(r4, r6, 1, 0)
     keep_alive r1
 L4:
     return 4
diff --git a/mypyc/test-data/irbuild-vectorcall.test b/mypyc/test-data/irbuild-vectorcall.test
index 17214f865f3ea..dec8c95f46d18 100644
--- a/mypyc/test-data/irbuild-vectorcall.test
+++ b/mypyc/test-data/irbuild-vectorcall.test
@@ -17,12 +17,12 @@ def f(c):
     r4 :: object_ptr
     r5 :: object
 L0:
-    r0 = _PyObject_Vectorcall(c, 0, 0, 0)
+    r0 = PyObject_Vectorcall(c, 0, 0, 0)
     r1 = 'x'
     r2 = 'y'
     r3 = [r1, r2]
     r4 = load_address r3
-    r5 = _PyObject_Vectorcall(c, r4, 2, 0)
+    r5 = PyObject_Vectorcall(c, r4, 2, 0)
     keep_alive r1, r2
     return 1
 
@@ -48,7 +48,7 @@ L0:
     r1 = [r0]
     r2 = load_address r1
     r3 = ('x',)
-    r4 = _PyObject_Vectorcall(c, r2, 0, r3)
+    r4 = PyObject_Vectorcall(c, r2, 0, r3)
     keep_alive r0
     r5 = 'x'
     r6 = 'y'
@@ -56,7 +56,7 @@ L0:
     r8 = [r5, r6, r7]
     r9 = load_address r8
     r10 = ('a', 'b')
-    r11 = _PyObject_Vectorcall(c, r9, 1, r10)
+    r11 = PyObject_Vectorcall(c, r9, 1, r10)
     keep_alive r5, r6, r7
     return 1
 
@@ -88,7 +88,7 @@ L0:
     r7 = [r3, r4]
     r8 = load_address r7
     r9 = ('a',)
-    r10 = _PyObject_Vectorcall(r6, r8, 1, r9)
+    r10 = PyObject_Vectorcall(r6, r8, 1, r9)
     keep_alive r3, r4
     return 1
 
diff --git a/mypyc/test-data/refcount.test b/mypyc/test-data/refcount.test
index 1169f848ca1f1..6b2b3d05fc192 100644
--- a/mypyc/test-data/refcount.test
+++ b/mypyc/test-data/refcount.test
@@ -695,7 +695,7 @@ L0:
     r2 = [x, r1]
     r3 = load_address r2
     r4 = ('base',)
-    r5 = _PyObject_Vectorcall(r0, r3, 1, r4)
+    r5 = PyObject_Vectorcall(r0, r3, 1, r4)
     r6 = unbox(int, r5)
     dec_ref r5
     return r6
@@ -890,7 +890,7 @@ L0:
     r0 = box(int, x)
     r1 = [r0]
     r2 = load_address r1
-    r3 = _PyObject_Vectorcall(f, r2, 1, 0)
+    r3 = PyObject_Vectorcall(f, r2, 1, 0)
     dec_ref r0
     r4 = unbox(int, r3)
     dec_ref r3