diff --git a/site/doc/api/math.generated.md b/site/doc/api/math.generated.md
index 095f935..c8e1f04 100644
--- a/site/doc/api/math.generated.md
+++ b/site/doc/api/math.generated.md
@@ -626,7 +626,10 @@ A complex number.
 out = 1 + 2i
 >>> i ^ 3
 # i ^ 3
-out = i
+out = -i
+>>> -5 + (-3i)
+# -5 + (-3 * i)
+out = -5 - 3i
 ```
 
 ## imag
diff --git a/src/Kalk.Core/KalkEngine.generated.cs b/src/Kalk.Core/KalkEngine.generated.cs
index 29198e3..6fcd986 100644
--- a/src/Kalk.Core/KalkEngine.generated.cs
+++ b/src/Kalk.Core/KalkEngine.generated.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Date: 25 Mar 2024
+//     Date: 26 Mar 2024
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -26955,7 +26955,10 @@ private void RegisterDocumentationAuto()
     out = 1 + 2i
     >>> i ^ 3
     # i ^ 3
-    out = i
+    out = -i
+    >>> -5 + (-3i)
+    # -5 + (-3 * i)
+    out = -5 - 3i
 ";
             }
             {
diff --git a/src/Kalk.Core/Model/KalkComplex.cs b/src/Kalk.Core/Model/KalkComplex.cs
index 6de699a..007b6d0 100644
--- a/src/Kalk.Core/Model/KalkComplex.cs
+++ b/src/Kalk.Core/Model/KalkComplex.cs
@@ -12,7 +12,7 @@ namespace Kalk.Core
 {
     public struct KalkComplex : IScriptCustomType, IKalkSpannable
     {
-        private Complex _value;
+        private readonly Complex _value;
         private const double MaxRoundToZero = 1e-14;
 
         public KalkComplex(double real, double im)
@@ -145,20 +145,35 @@ public override string ToString()
             var re = Math.Round(Re, 10, MidpointRounding.AwayFromZero);
             var im = Math.Round(Im, 10, MidpointRounding.AwayFromZero);
 
-            if (Math.Abs(re) > 1e-14) builder.AppendFormat(CultureInfo.CurrentCulture, "{0}", re);
+            if (Math.Abs(re) > MaxRoundToZero) builder.AppendFormat(CultureInfo.CurrentCulture, "{0}", re);
 
             if (HasIm)
             {
-                if (builder.Length > 0) builder.Append(" + ");
-
-                if (Math.Abs(Math.Abs(im) - 1.0) < MaxRoundToZero)
+                if (builder.Length > 0)
                 {
-                    builder.Append("i");
+                    builder.Append(im < 0 ? " - " : " + ");
+
+                    if (Math.Abs(Math.Abs(im) - 1.0) < MaxRoundToZero)
+                    {
+                        builder.Append("i");
+                    }
+                    else
+                    {
+                        builder.AppendFormat(CultureInfo.CurrentCulture, "{0}i", Math.Abs(im));
+                    }
                 }
                 else
                 {
-                    builder.AppendFormat(CultureInfo.CurrentCulture, "{0}i", im);
+                    if (Math.Abs(Math.Abs(im) - 1.0) < MaxRoundToZero)
+                    {
+                        builder.Append( im <  0 ? "-i" : "i");
+                    }
+                    else
+                    {
+                        builder.AppendFormat(CultureInfo.CurrentCulture, "{0}i", im);
+                    }
                 }
+
             }
 
             if (builder.Length == 0) builder.Append("0");
diff --git a/src/Kalk.Core/Modules/MathModule.cs b/src/Kalk.Core/Modules/MathModule.cs
index e3cc2e1..3270e56 100644
--- a/src/Kalk.Core/Modules/MathModule.cs
+++ b/src/Kalk.Core/Modules/MathModule.cs
@@ -147,7 +147,10 @@ public MathModule()
         /// out = 1 + 2i
         /// >>> i ^ 3
         /// # i ^ 3
-        /// out = i
+        /// out = -i
+        /// >>> -5 + (-3i)
+        /// # -5 + (-3 * i)
+        /// out = -5 - 3i
         /// ```
         /// </example>
         [KalkExport("i", CategoryMathFunctions)]
diff --git a/src/Kalk.Tests/KalkTests.generated.cs b/src/Kalk.Tests/KalkTests.generated.cs
index 10384ef..d2398b6 100644
--- a/src/Kalk.Tests/KalkTests.generated.cs
+++ b/src/Kalk.Tests/KalkTests.generated.cs
@@ -1,7 +1,7 @@
 //------------------------------------------------------------------------------
 // <auto-generated>
 //     This code was generated by a tool.
-//     Date: 25 Mar 2024
+//     Date: 26 Mar 2024
 //
 //     Changes to this file may cause incorrect behavior and will be lost if
 //     the code is regenerated.
@@ -905,10 +905,13 @@ public partial class MathModuleTests : KalkTestBase
         /// Test for <see cref="M:Kalk.Core.MathModule.ComplexNumber"/> or `i`.
         /// </summary>
         [TestCase(@"1 + 2i
-i ^ 3", @"# 1 + 2 * i
+i ^ 3
+-5 + (-3i)", @"# 1 + 2 * i
 out = 1 + 2i
 # i ^ 3
-out = i", Category = "Math Functions")]
+out = -i
+# -5 + (-3 * i)
+out = -5 - 3i", Category = "Math Functions")]
         public static void Test_i(string input, string output) => AssertScript(input, output);
 
         /// <summary>