diff --git a/lang/interpret_test/TestAstFunc2/lexer-parser0.txtar b/lang/interpret_test/TestAstFunc2/lexer-parser0.txtar
new file mode 100644
index 00000000..d12ca1bc
--- /dev/null
+++ b/lang/interpret_test/TestAstFunc2/lexer-parser0.txtar
@@ -0,0 +1,16 @@
+-- main.mcl --
+import "fmt"
+
+$map = 55
+$fn = func($in) { # in is a special keyword
+	13
+}
+test fmt.printf("%d", $fn(0)) {}
+func fn($in) { # in is a special keyword
+	42 + $map
+}
+test fmt.printf("%d", $fn(0)) {}
+test fmt.printf("%d", fn(0)) {}
+-- OUTPUT --
+Vertex: test[13]
+Vertex: test[97]
diff --git a/lang/parser/lexer.nex b/lang/parser/lexer.nex
index 29fa39f7..13251819 100644
--- a/lang/parser/lexer.nex
+++ b/lang/parser/lexer.nex
@@ -139,11 +139,6 @@
 			lval.str = yylex.Text()
 			return NOT
 		}
-/in/		{
-			yylex.pos(lval) // our pos
-			lval.str = yylex.Text()
-			return IN
-		}
 /\->/		{
 			yylex.pos(lval) // our pos
 			lval.str = yylex.Text()
@@ -306,6 +301,11 @@
 			lval.str = yylex.Text()
 			return IDENTIFIER
 		}
+/in/		{
+			yylex.pos(lval) // our pos
+			lval.str = yylex.Text()
+			return IN
+		}
 /[A-Z]([a-z0-9_]*[a-z0-9]+)?/
 		{
 			yylex.pos(lval) // our pos