diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index f82b102..75e8da4 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1031,10 +1031,12 @@
 tok_backup(struct tok_state *tok, int c)
 {
     if (c != EOF) {
-        if (--tok->cur < tok->buf)
-            Py_FatalError("tok_backup: beginning of buffer");
-        if (*tok->cur != c)
+        if (--tok->cur < tok->buf) {
+            Py_FatalError("beginning of buffer");
+        }
+        if (*tok->cur != c) {
             *tok->cur = c;
+        }
     }
 }