diff --git a/src/Microsoft.Windows.CsWin32/Generator.FriendlyOverloads.cs b/src/Microsoft.Windows.CsWin32/Generator.FriendlyOverloads.cs
index a2441225..60fdb713 100644
--- a/src/Microsoft.Windows.CsWin32/Generator.FriendlyOverloads.cs
+++ b/src/Microsoft.Windows.CsWin32/Generator.FriendlyOverloads.cs
@@ -989,7 +989,7 @@ private IEnumerable<MethodDeclarationSyntax> DeclareFriendlyOverload(
                 parameters[paramIndex] = externParam
                     .WithType(PredefinedType(TokenWithSpace(SyntaxKind.StringKeyword)));
 
-                // fixed (byte* someLocal = some is object ? System.Text.Encoding.Default.GetBytes(some) : null)
+                // fixed (byte* someLocal = some is object ? System.Text.Encoding.Default.GetBytes(some + "\0") : null)
                 fixedBlocks.Add(VariableDeclaration(
                     PointerType(PredefinedType(Token(SyntaxKind.ByteKeyword))),
                     [
@@ -1003,7 +1003,12 @@ private IEnumerable<MethodDeclarationSyntax> DeclareFriendlyOverload(
                                             SyntaxKind.SimpleMemberAccessExpression,
                                             ParseTypeName("global::System.Text.Encoding.Default"),
                                             IdentifierName(nameof(Encoding.GetBytes))),
-                                        [Argument(origName)]),
+                                        [
+                                            Argument(BinaryExpression(
+                                                SyntaxKind.AddExpression,
+                                                origName,
+                                                LiteralExpression(SyntaxKind.StringLiteralExpression, Literal("\0"))))
+                                        ]),
                                     LiteralExpression(SyntaxKind.NullLiteralExpression))))
                     ]));
 
diff --git a/test/GenerationSandbox.Tests/BasicTests.cs b/test/GenerationSandbox.Tests/BasicTests.cs
index c671b769..cbf827e9 100644
--- a/test/GenerationSandbox.Tests/BasicTests.cs
+++ b/test/GenerationSandbox.Tests/BasicTests.cs
@@ -434,6 +434,13 @@ public unsafe void GetProcAddress_String()
         Assert.NotEqual(0u, ticks);
     }
 
+    [Fact]
+    public void PCSTR_StringOverloadNullTerminates()
+    {
+        const string value = "12345678";
+        Assert.Equal(value.Length, PInvoke.lstrlen(value));
+    }
+
     [Fact]
     public void StructCharFieldsMarshaledAsUtf16()
     {
diff --git a/test/GenerationSandbox.Tests/NativeMethods.txt b/test/GenerationSandbox.Tests/NativeMethods.txt
index d0e25726..84a6cba0 100644
--- a/test/GenerationSandbox.Tests/NativeMethods.txt
+++ b/test/GenerationSandbox.Tests/NativeMethods.txt
@@ -48,6 +48,7 @@ IShellWindows
 IStream
 KEY_EVENT_RECORD
 LoadLibrary
+lstrlen
 LOWORD
 MainAVIHeader
 MAKELPARAM