diff --git a/setup.py b/setup.py
index 2915b8d..fc66bc3 100644
--- a/setup.py
+++ b/setup.py
@@ -153,7 +153,7 @@
     srcs.append('_doubleloadtester.cpp', )
 
 ext_modules.append(
-    Extension('pycryptopp._pycryptopp', extra_srcs + srcs, include_dirs=include_dirs, library_dirs=library_dirs, libraries=libraries, extra_link_args=extra_link_args, extra_compile_args=extra_compile_args, define_macros=define_macros, undef_macros=undef_macros)
+    Extension('pycryptopp._pycryptopp', sorted(extra_srcs) + srcs, include_dirs=include_dirs, library_dirs=library_dirs, libraries=libraries, extra_link_args=extra_link_args, extra_compile_args=extra_compile_args, define_macros=define_macros, undef_macros=undef_macros)
     )
 
 # python-ed25519
@@ -163,7 +163,7 @@
                 if s.endswith(".c") and s!="test.c"])
 m = Extension("pycryptopp.publickey.ed25519._ed25519",
               include_dirs=[os.path.join("src-ed25519","supercop-ref")],
-              sources=sources)
+              sources=sorted(sources))
 ext_modules.append(m)
 
 
diff --git a/src-cryptopp/GNUmakefile b/src-cryptopp/GNUmakefile
index 2a0ff4c..6390669 100755
--- a/src-cryptopp/GNUmakefile
+++ b/src-cryptopp/GNUmakefile
@@ -413,7 +413,7 @@ endif # HAS_SOLIB_VERSION
 ###########################################################
 
 # List cryptlib.cpp first, then cpu.cpp, then integer.cpp to tame C++ static initialization problems.
-SRCS := cryptlib.cpp cpu.cpp integer.cpp $(filter-out cryptlib.cpp cpu.cpp integer.cpp pch.cpp simple.cpp winpipes.cpp cryptlib_bds.cpp,$(wildcard *.cpp))
+SRCS := cryptlib.cpp cpu.cpp integer.cpp $(filter-out cryptlib.cpp cpu.cpp integer.cpp pch.cpp simple.cpp winpipes.cpp cryptlib_bds.cpp,$(sort $(wildcard *.cpp)))
 
 # Need CPU for X86/X64/X32 and ARM
 ifeq ($(IS_X86)$(IS_X64)$(IS_ARM32)$(IS_ARM64),0000)