diff --git a/chapi-ast-c/src/main/antlr/C.g4 b/chapi-ast-c/src/main/antlr/C.g4
index 03626900..8de6a1c7 100644
--- a/chapi-ast-c/src/main/antlr/C.g4
+++ b/chapi-ast-c/src/main/antlr/C.g4
@@ -475,10 +475,10 @@ macroStatement
 
 singleLineMacroDeclaration
     : include (StringLiteral | Identifier | ('<' includeIdentifier '>' ))            #includeDeclaration
-    | macroKeywords Identifier? expression* '#' macroKeywords identifierList?        #ifdefDeclaration
     // #define LUAI_USER_ALIGNMENT_T	union { double u; void *s; long l; }
-    | macroKeywords                                                                  #defineDeclaration
-    | 'define' Identifier structOrUnionSpecifier                                     #macroFunctionDeclaration
+    | macroKeywords Identifier? (structOrUnionSpecifier | expression)*
+                ('#' macroKeywords)? identifierList?                                  #ifdefDeclaration
+//    | macroKeywords                                                                  #defineDeclaration
     | '#'? Identifier                                                                #macroCastDeclaration
 //    | 'define' expression* '#' 'undef' identifierList?                               #macroExpansionDeclaration
 //    | macroKeywords expression* '#' macroKeywords identifierList?                    #macroExpansionDeclaration2