diff --git a/src/core/function-def.js b/src/core/function-def.js
index 0d0d046d..d8751610 100644
--- a/src/core/function-def.js
+++ b/src/core/function-def.js
@@ -72,6 +72,7 @@ class FunctionDef extends Top {
         let msg = this.id + ': '+ e.message + ` in "${q.math.toString()}"`;
         logger && logger.error(msg, {type: 'ValidationError'});
         this.errored = true;
+        return; // BRAKE
       }
 
       // check that identifiers in `math` correspond to `arguments`