diff --git a/Source/exehead/exec.c b/Source/exehead/exec.c
index 6db2c25b..85005a35 100644
--- a/Source/exehead/exec.c
+++ b/Source/exehead/exec.c
@@ -64,11 +64,15 @@ int NSISCALL ExecuteCodeSegment(int pos, HWND hwndProgress)
   return 0;
 }
 
+#ifdef NSIS_SUPPORT_CODECALLBACKS
+
 int NSISCALL ExecuteCallbackFunction(int num)
 {
   return ExecuteCodeSegment(*(&g_header->code_onInit + num), NULL);
 }
 
+#endif
+
 static char bufs[5][NSIS_MAX_STRLEN];
 static int *parms;