diff --git a/CHERICap.bsv b/CHERICap.bsv
index 37dba33..51339d3 100644
--- a/CHERICap.bsv
+++ b/CHERICap.bsv
@@ -189,14 +189,13 @@ typeclass CHERICap#(type t, numeric type ot, numeric type flg, numeric type n, n
   // base.
   function Bit#(2) getBaseAlignment (t cap);
 
-  // TODO the following do not compile due to "not enough explicit type information"
   // Get representable alignment mask
-  // function Bit#(n) getRepresentableAlignmentMask (t dummy, Bit#(n) length_request) =
-  //   setBoundsCombined(nullCap, length_request).mask;
+  function Bit#(n) getRepresentableAlignmentMask (t dummy, Bit#(n) length_request) =
+    setBoundsCombined(nullCapFromDummy(dummy), length_request).mask;
 
   // Get representable length
-  // function Bit#(n) getRepresentableLength (t dummy, Bit#(n) length_request) =
-  //   setBoundsCombined(nullCap, length_request).length;
+  function Bit#(n) getRepresentableLength (t dummy, Bit#(n) length_request) =
+    setBoundsCombined(nullCapFromDummy(dummy), length_request).length;
 
   // Assert that the encoding is valid
   function Bool isDerivable (t cap);