diff --git a/Include/bitset.h b/Include/bitset.h
index 6fa5be6..9be259a 100644
--- a/Include/bitset.h
+++ b/Include/bitset.h
@@ -36,7 +36,7 @@
 
 bitset newbitset PROTO((int nbits));
 void delbitset PROTO((bitset bs));
-/* int testbit PROTO((bitset bs, int ibit)); /* Now a macro, see below */
+#define testbit(ss, ibit) (((ss)[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0)
 int addbit PROTO((bitset bs, int ibit)); /* Returns 0 if already set */
 int samebitset PROTO((bitset bs1, bitset bs2, int nbits));
 void mergebitset PROTO((bitset bs1, bitset bs2, int nbits));
@@ -49,8 +49,6 @@
 #define BIT2MASK(ibit)	(1 << BIT2SHIFT(ibit))
 #define BYTE2BIT(ibyte)	((ibyte) * BITSPERBYTE)
 
-#define testbit(ss, ibit) (((ss)[BIT2BYTE(ibit)] & BIT2MASK(ibit)) != 0)
-
 #ifdef __cplusplus
 }
 #endif