diff --git a/tests/baz/1.0/IBase.hal b/tests/baz/1.0/IBase.hal
index 7f90f16..d5e3565 100644
--- a/tests/baz/1.0/IBase.hal
+++ b/tests/baz/1.0/IBase.hal
@@ -64,6 +64,19 @@
         vec<MacAddress> addresses;
     };
 
+    enum BitField : uint8_t {
+        V0 = 1 << 0,
+        V1 = 1 << 1,
+        V2 = 1 << 2,
+        V3 = 1 << 3,
+    };
+
+    struct MyMask {
+        bitfield<BitField> value;
+    };
+
+    typedef bitfield<BitField> Mask;
+
     someBaseMethod();
 
     someBoolMethod(bool x) generates (bool y);
@@ -81,4 +94,7 @@
 
     transpose(StringMatrix5x3 in) generates (StringMatrix3x5 out);
     transpose2(ThreeStrings[5] in) generates (FiveStrings[3] out);
+
+    takeAMask(BitField bf, bitfield<BitField> first, MyMask second, Mask third)
+            generates (BitField out, uint8_t f, uint8_t s, uint8_t t);
 };