diff --git a/lang/interpret_test/TestAstFunc2/struct-duplicate4.output b/lang/interpret_test/TestAstFunc2/struct-duplicate4.output
new file mode 100644
index 00000000..5d8fb049
--- /dev/null
+++ b/lang/interpret_test/TestAstFunc2/struct-duplicate4.output
@@ -0,0 +1 @@
+# err: err1: parser: `syntax error: unexpected $end, expecting EQUALS` @1:6
diff --git a/lang/interpret_test/TestAstFunc2/struct-duplicate4/main.mcl b/lang/interpret_test/TestAstFunc2/struct-duplicate4/main.mcl
new file mode 100644
index 00000000..7cc41f75
--- /dev/null
+++ b/lang/interpret_test/TestAstFunc2/struct-duplicate4/main.mcl
@@ -0,0 +1 @@
+$d []struct{x int;x float}
diff --git a/lang/parser.y b/lang/parser.y
index 569a1d1f..6ea9c5cf 100644
--- a/lang/parser.y
+++ b/lang/parser.y
@@ -1180,14 +1180,14 @@ type:
 		strs := []string{}
 		for _, arg := range $3.args {
 			s := fmt.Sprintf("%s %s", arg.Name, arg.Type.String())
-			if _, exists := names[s]; exists {
+			if _, exists := names[arg.Name]; exists {
 				// duplicate field name used
 				err := fmt.Errorf("duplicate struct field of `%s`", s)
 				// this will ultimately cause a parser error to occur...
 				yylex.Error(fmt.Sprintf("%s: %+v", ErrParseSetType, err))
 				break // we must skip, because code continues!
 			}
-			names[s] = struct{}{}
+			names[arg.Name] = struct{}{}
 			strs = append(strs, s)
 		}