diff --git a/cmsg_private.h b/cmsg_private.h
index 48e3412..f33dd1f 100644
--- a/cmsg_private.h
+++ b/cmsg_private.h
@@ -14,8 +14,8 @@ extern cmsg_bytes_t cmsg_bytes_malloc(size_t amount);
 extern void cmsg_bytes_free(cmsg_bytes_t bytes);
 
 #define ICHECK(result, message) do { if ((result) == -1) { perror(message); exit(2); } } while (0)
-#define BCHECK(result, message) do { if (!(result)) { perror(message); exit(2); } } while (0)
-#define PCHECK(result, message) do { if (!(result)) { perror(message); exit(2); } } while (0)
+#define BCHECK(result, message) do { if ((result) == 0) { perror(message); exit(2); } } while (0)
+#define PCHECK(result, message) do { if ((result) == NULL) { perror(message); exit(2); } } while (0)
 
 extern void die(char const *format, ...);
 extern void warn(char const *format, ...);