diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 1ce17f5..891fba6 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -171,6 +171,7 @@
         }                                                                   \
         memcpy(param_fail_jmp, jmp_tmp, sizeof(jmp_buf));                   \
     } while( 0 )
+#endif /* MBEDTLS_CHECK_PARAMS && !MBEDTLS_PARAM_FAILED_ALT */
 
 /**
  * \brief   This macro tests the statement passed to it as a test step or
@@ -195,11 +196,16 @@
  *          accept is best done by using TEST_ASSERT() and checking the return
  *          value as well.
  *
+ *          Note: this macro is available even when #MBEDTLS_CHECK_PARAMS is
+ *          disabled, as it makes sense to check that the functions accept all
+ *          legal values even if this option is disabled - only in that case,
+ *          the test if more about whether the function segfaults than about
+ *          whether it invokes MBEDTLS_PARAM_FAILED().
+ *
  * \param   TEST                The test expression to be tested.
  */
 #define TEST_VALID_PARAM( TEST )                                    \
     TEST_ASSERT( ( TEST, 1 ) );
-#endif /* MBEDTLS_CHECK_PARAMS && !MBEDTLS_PARAM_FAILED_ALT */
 
 #define assert(a) if( !( a ) )                                      \
 {                                                                   \