diff --git a/preproc.c b/preproc.c
index 14c32149..845f8fc1 100644
--- a/preproc.c
+++ b/preproc.c
@@ -389,7 +389,7 @@ static const char * const tasm_directives[] = {
 };
 
 static int StackSize = 4;
-static char *StackPointer = "ebp";
+static const char *StackPointer = "ebp";
 static int ArgOffset = 8;
 static int LocalOffset = 0;