diff --git a/src/cc65/stmt.c b/src/cc65/stmt.c
index 0c891c386..a9552ba96 100644
--- a/src/cc65/stmt.c
+++ b/src/cc65/stmt.c
@@ -513,7 +513,7 @@ static int CompoundStatement (void)
 
     /* Remember the stack at block entry */
     int OldStack = StackPtr;
-    long OldBlockStackSize = CollCount (&CurrentFunc->LocalsBlockStack);
+    unsigned OldBlockStackSize = CollCount (&CurrentFunc->LocalsBlockStack);
 
     /* Enter a new lexical level */
     EnterBlockLevel ();