diff --git a/src/parser/parser.yc b/src/parser/parser.yc
index 3183c5e..173dd05 100644
--- a/src/parser/parser.yc
+++ b/src/parser/parser.yc
@@ -264,6 +264,7 @@ assignment_operator
 
 expression
     : assignment_expression
+    | EXTENSION assignment_expression
     | expression COMMA assignment_expression
     ;