diff --git a/Source/exehead/Main.c b/Source/exehead/Main.c
index 4f16683d..ec4c2224 100644
--- a/Source/exehead/Main.c
+++ b/Source/exehead/Main.c
@@ -140,7 +140,7 @@ int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInst,LPSTR lpszCmdParam,
 
       if (*(LPDWORD)(cmdline-2) == CHAR4_TO_DWORD(' ', '/', 'D','='))
       {
-        cmdline[-2]=0; // keep this from being passed to uninstaller if necessary
+        *(LPDWORD)(cmdline-2)=0; // keep this from being passed to uninstaller if necessary
         mystrcpy(state_install_directory,cmdline+2);
         break; // /D= must always be last
       }