diff --git a/include/cryb/test.h b/include/cryb/test.h
index 93543fb..b745977 100644
--- a/include/cryb/test.h
+++ b/include/cryb/test.h
@@ -118,7 +118,7 @@ t_compare_num(x32, uint32_t);
 t_compare_num(i64, int64_t);
 t_compare_num(u64, uint64_t);
 t_compare_num(x64, uint64_t);
-t_compare_num(ptr, void *);
+t_compare_num(ptr, const void *);
 #undef t_compare_num
 
 int t_str_is_true(const char *);
diff --git a/lib/test/cryb_t_compare.c b/lib/test/cryb_t_compare.c
index 8da5102..a3409ab 100644
--- a/lib/test/cryb_t_compare.c
+++ b/lib/test/cryb_t_compare.c
@@ -154,7 +154,7 @@ t_compare_num(x32,	uint32_t,		"0x%" PRIx32);
 t_compare_num(i64,	int64_t,		"%" PRId64);
 t_compare_num(u64,	uint64_t,		"%" PRIu64);
 t_compare_num(x64,	uint64_t,		"0x%" PRIx64);
-t_compare_num(ptr,	void *,			"%p");
+t_compare_num(ptr,	const void *,		"%p");
 
 #undef t_compare_num