diff --git a/src/asm/fstack.cpp b/src/asm/fstack.cpp
index 735cbf42..53276d7b 100644
--- a/src/asm/fstack.cpp
+++ b/src/asm/fstack.cpp
@@ -417,6 +417,14 @@ void fstk_RunMacro(
 			    macroName.c_str(),
 			    defType
 			);
+		} else if (std::shared_ptr<std::string> firstArg = macroArgs->getArg(1);
+		           firstArg && firstArg->starts_with(':')) {
+			error(
+			    "Undefined macro `%s` (did you mean a label \"%s%s\"?)",
+			    macroName.c_str(),
+			    macroName.c_str(),
+			    firstArg->starts_with("::") ? "::" : ":"
+			);
 		} else {
 			error("Undefined macro `%s`", macroName.c_str());
 		}
diff --git a/test/asm/lexer-hack.asm b/test/asm/lexer-hack.asm
index 83e2d41b..553b058a 100644
--- a/test/asm/lexer-hack.asm
+++ b/test/asm/lexer-hack.asm
@@ -23,6 +23,6 @@ Label2: ld d, 4
 ; and a label definition when already defined as a macro
 mac: ld e, 5
 
-; the space before the colon matters!
+; the space before the colon matters! the space before the macro does not
 	undef :
-undef :
+undef ::
diff --git a/test/asm/lexer-hack.err b/test/asm/lexer-hack.err
index f1b7c5ba..bce134ab 100644
--- a/test/asm/lexer-hack.err
+++ b/test/asm/lexer-hack.err
@@ -4,8 +4,8 @@ error: `mac` already defined
     at lexer-hack.asm(24)
     and also:
     at lexer-hack.asm(1)
-error: Undefined macro `undef`
+error: Undefined macro `undef` (did you mean a label "undef:"?)
     at lexer-hack.asm(27)
-error: Undefined macro `undef`
+error: Undefined macro `undef` (did you mean a label "undef::"?)
     at lexer-hack.asm(28)
 Assembly aborted with 4 errors!