diff --git a/test/testutil.h b/test/testutil.h
index 1ca295cc1638d7ccf9420b2fb9d53c3ae6be05da..a83323b9e89c0cb858f6c16351220e3108fa77c0 100644
--- a/test/testutil.h
+++ b/test/testutil.h
@@ -291,8 +291,8 @@ void test_info_c90(const char *desc, ...) PRINTF_FORMAT(1, 2);
 # define TEST_mem_eq(a, m, b, n) test_mem_eq(__FILE__, __LINE__, #a, #b, a, m, b, n)
 # define TEST_mem_ne(a, m, b, n) test_mem_ne(__FILE__, __LINE__, #a, #b, a, m, b, n)
 
-# define TEST_true(a)         test_true(__FILE__, __LINE__, #a, a)
-# define TEST_false(a)        test_false(__FILE__, __LINE__, #a, a)
+# define TEST_true(a)         test_true(__FILE__, __LINE__, #a, (a) != 0)
+# define TEST_false(a)        test_false(__FILE__, __LINE__, #a, (a) != 0)
 
 /*
  * TEST_error(desc, ...) prints an informative error message in the standard