diff --git a/bip-???-cat.mediawiki b/bip-???-cat.mediawiki
index 68336211..584f697f 100644
--- a/bip-???-cat.mediawiki
+++ b/bip-???-cat.mediawiki
@@ -50,8 +50,9 @@ case OP_CAT:
     }
     valtype& vch1 = stacktop(-2);
     valtype& vch2 = stacktop(-1);
-    if (vch1.size() + vch2.size() > MAX_SCRIPT_ELEMENT_SIZE)
+    if (vch1.size() + vch2.size() > MAX_SCRIPT_ELEMENT_SIZE) {
         return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
+    }
     vch1.insert(vch1.end(), vch2.begin(), vch2.end());
     stack.pop_back();
 }