diff --git a/dlls/cstrike/Makefile.pl b/dlls/cstrike/Makefile.pl
index ed87871b..31c2d66e 100755
--- a/dlls/cstrike/Makefile.pl
+++ b/dlls/cstrike/Makefile.pl
@@ -73,7 +73,7 @@ if ($OPTIONS{"debug"})
 
 if ($OPTIONS{"amd64"})
 {
-	$cflags .= "-m64 -DSMALL_CELLSIZE=64 $cflags";
+	$cflags = " -m64 -DSMALL_CELL_SIZE=64 $cflags";
 }
 
 if ($OPTIONS{"debug"})