diff --git a/tests/jwt_tests.h b/tests/jwt_tests.h
index ae8600a9..9b2eb8e2 100644
--- a/tests/jwt_tests.h
+++ b/tests/jwt_tests.h
@@ -20,14 +20,19 @@
 #endif
 
 /* Compatibility with older libCheck versions */
-/* Older check doesn't have this. */
 #ifndef ck_assert_ptr_ne
-#define ck_assert_ptr_ne(X, Y) ck_assert(X != Y)
-#define ck_assert_ptr_eq(X, Y) ck_assert(X == Y)
+#define ck_assert_ptr_ne(__X, __Y) ck_assert(__X != __Y)
+#define ck_assert_ptr_eq(__X, __Y) ck_assert(__X == __Y)
 #endif
 
 #ifndef ck_assert_int_gt
-#define ck_assert_int_gt(X, Y) ck_assert(X > Y)
+#define ck_assert_int_gt(__X, __Y) ck_assert(__X > __Y)
+#define ck_assert_int_lt(__X, __Y) ck_assert(__X < __Y)
+#endif
+
+#ifndef ck_assert_ptr_null
+#define ck_assert_ptr_null(__X) ck_assert(__X == NULL)
+#define ck_assert_ptr_nonnull(__X) ck_assert(__X != NULL)
 #endif
 
 /* Constant time to make tests consistent. */