diff --git a/panda/src/putil/bitMask.I b/panda/src/putil/bitMask.I
index 53bdbe48fd..125bf564d1 100644
--- a/panda/src/putil/bitMask.I
+++ b/panda/src/putil/bitMask.I
@@ -833,17 +833,6 @@ operator WType () const {
   return _word;
 }
 
-////////////////////////////////////////////////////////////////////
-//     Function: BitMask::operator bool
-//       Access: Published
-//  Description: Will return true, unless all bits are off.
-////////////////////////////////////////////////////////////////////
-template<class WType, int nbits>
-INLINE BitMask<WType, nbits>::
-operator bool () const {
-  return (_word != 0);
-}
-
 ////////////////////////////////////////////////////////////////////
 //     Function: BitMask::get_key
 //       Access: Published
diff --git a/panda/src/putil/bitMask.h b/panda/src/putil/bitMask.h
index fdc3b58fc1..318ced9665 100644
--- a/panda/src/putil/bitMask.h
+++ b/panda/src/putil/bitMask.h
@@ -118,6 +118,8 @@ PUBLISHED:
   INLINE void operator <<= (int shift);
   INLINE void operator >>= (int shift);
 
+  INLINE operator WType () const;
+
   INLINE void flood_down_in_place();
   INLINE void flood_up_in_place();
   INLINE BitMask<WType, nbits> flood_bits_down() const;