diff --git a/dix/resource.c b/dix/resource.c
index a42cd007f..6c0be2e04 100644
--- a/dix/resource.c
+++ b/dix/resource.c
@@ -671,7 +671,7 @@ InitClientResources(ClientPtr client)
 }
 
 int
-HashResourceID(XID id, int numBits)
+HashResourceID(XID id, unsigned int numBits)
 {
     static XID mask;
 
@@ -679,7 +679,7 @@ HashResourceID(XID id, int numBits)
         mask = RESOURCE_ID_MASK;
     id &= mask;
     if (numBits < 9)
-        return (id ^ (id >> numBits) ^ (id >> (numBits<<1))) & ~((~0) << numBits);
+        return (id ^ (id >> numBits) ^ (id >> (numBits<<1))) & ~((~0U) << numBits);
     return (id ^ (id >> numBits)) & ~((~0) << numBits);
 }
 
diff --git a/include/resource.h b/include/resource.h
index 5871a4cb4..6caf846c4 100644
--- a/include/resource.h
+++ b/include/resource.h
@@ -270,7 +270,6 @@ extern _X_EXPORT RESTYPE TypeMask;
     of bits by either masking numBits lower bits of the ID or by
     providing at most MAXHASHSIZE hashes.
 */
-extern _X_EXPORT int HashResourceID(XID id,
-                                    int numBits);
+extern _X_EXPORT int HashResourceID(XID id, unsigned int numBits);
 
 #endif /* RESOURCE_H */