1 files changed, 1 insertions, 1 deletions

diff --git a/src/yuescript/yue_parser.cpp b/src/yuescript/yue_parser.cpp
index 255469d..c79d58e 100644
--- a/src/yuescript/yue_parser.cpp
+++ b/src/yuescript/yue_parser.cpp
@@ -548,7 +548,7 @@ YueParser::YueParser() {
         KeyValueList = KeyValue >> *(sym(',') >> KeyValue);
         KeyValueLine = CheckIndent >> (KeyValueList >> -sym(',') | TableBlockIndent | Space >> expr('*') >> (Exp | TableBlock));
 
-        FnArgDef = (Variable | SelfName) >> -(sym('=') >> Space >> Exp);
+        FnArgDef = (Variable | SelfName >> -existential_op) >> -(sym('=') >> Space >> Exp);
 
         FnArgDefList = Space >> Seperator >> (
                 (