diff --git a/src/reflect.zig b/src/reflect.zig
index f01b4a8..8f63268 100644
--- a/src/reflect.zig
+++ b/src/reflect.zig
@@ -229,6 +229,14 @@ pub const Type = struct {
             under_ptr = info.Pointer.child;
         }
 
+        // variadic types must be optional
+        if (under_opt == null) {
+            const under = under_ptr orelse T;
+            if (Type._is_variadic(under)) {
+                return error.TypeVariadicNotOptional;
+            }
+        }
+
         var t = Type{
             .T = T,
             .name = name,
@@ -1238,6 +1246,7 @@ const Error = error{
     TypeTaggedUnion,
     TypeNestedPtr,
     TypeVariadicNested, // TODO: test
+    TypeVariadicNotOptional,
     TypeLookup,
 };
 
@@ -1336,10 +1345,10 @@ const TestFuncMultiCbk = struct {
 };
 const VariadicBool = Variadic(bool);
 const TestFuncVariadicNotLastOne = struct {
-    pub fn _example(_: TestFuncVariadicNotLastOne, _: VariadicBool, _: bool) void {}
+    pub fn _example(_: TestFuncVariadicNotLastOne, _: ?VariadicBool, _: bool) void {}
 };
 const TestFuncReturnTypeVariadic = struct {
-    pub fn _example(_: TestFuncReturnTypeVariadic) VariadicBool {}
+    pub fn _example(_: TestFuncReturnTypeVariadic) ?VariadicBool {}
 };
 
 // types tests
@@ -1354,6 +1363,9 @@ const TestTypeNestedPtr = struct {
     pub const TestTypeNestedBase = struct {};
     pub fn _example(_: TestTypeNestedPtr, _: *TestTypeNestedBase) void {}
 };
+const TestTypeVariadicNotOptional = struct {
+    pub fn _example(_: TestTypeVariadicNotOptional, _: VariadicBool) void {}
+};
 const TestType = struct {};
 const TestTypeLookup = struct {
     pub fn _example(_: TestTypeLookup, _: TestType) void {}
@@ -1464,6 +1476,10 @@ pub fn tests() !void {
         .{TestTypeNestedPtr},
         error.TypeNestedPtr,
     );
+    try ensureErr(
+        .{TestTypeVariadicNotOptional},
+        error.TypeVariadicNotOptional,
+    );
     try ensureErr(
         .{TestTypeLookup},
         error.TypeLookup,
diff --git a/src/tests/types_complex_test.zig b/src/tests/types_complex_test.zig
index 22d8ffd..05a19f2 100644
--- a/src/tests/types_complex_test.zig
+++ b/src/tests/types_complex_test.zig
@@ -34,16 +34,20 @@ const MyVariadic = struct {
         return .{ .member = 0 };
     }
 
-    pub fn _len(_: MyVariadic, variadic: VariadicBool) u64 {
-        return @as(u64, variadic.slice.len);
+    pub fn _len(_: MyVariadic, variadic: ?VariadicBool) u64 {
+        return @as(u64, variadic.?.slice.len);
     }
 
-    pub fn _first(_: MyVariadic, _: []const u8, variadic: VariadicBool) bool {
-        return variadic.slice[0];
+    pub fn _first(_: MyVariadic, _: []const u8, variadic: ?VariadicBool) bool {
+        return variadic.?.slice[0];
     }
 
-    pub fn _last(_: MyVariadic, variadic: VariadicBool) bool {
-        return variadic.slice[variadic.slice.len - 1];
+    pub fn _last(_: MyVariadic, variadic: ?VariadicBool) bool {
+        return variadic.?.slice[variadic.?.slice.len - 1];
+    }
+
+    pub fn _empty(_: MyVariadic, _: ?VariadicBool) bool {
+        return true;
     }
 };
 
@@ -82,6 +86,7 @@ pub fn exec(
         .{ .src = "myVariadic.len(true, false, true)", .ex = "3" },
         .{ .src = "myVariadic.first('a_str', true, false, true, false)", .ex = "true" },
         .{ .src = "myVariadic.last(true, false)", .ex = "false" },
+        .{ .src = "myVariadic.empty()", .ex = "true" },
     };
     try tests.checkCases(js_env, &variadic);
 }