diff --git a/reframe/core/pipeline.py b/reframe/core/pipeline.py
index 5bb21eeb3c..298ee257b8 100644
--- a/reframe/core/pipeline.py
+++ b/reframe/core/pipeline.py
@@ -1134,14 +1134,20 @@ def check_performance(self):
                         "tag `%s' not resolved in references for `%s'" %
                         (tag, self._current_partition.fullname))
 
-                self._perfvalues[key] = (value, *self.reference[key])
+                self._perfvalues[key] = (tag, value, *self.reference[key])
                 self._perf_logger.log_performance(logging.INFO, tag, value,
                                                   *self.reference[key])
 
-            for val, *reference in self._perfvalues.values():
-                ref, low_thres, high_thres, *_ = reference
+            for values in self._perfvalues.values():
+                tag, val, ref, low_thres, high_thres, *_ = values
                 try:
-                    evaluate(assert_reference(val, ref, low_thres, high_thres))
+                    evaluate(
+                        assert_reference(
+                            val, ref, low_thres, high_thres,
+                            msg=('failed to meet reference: %s={0}, '
+                                 'expected {1} (l={2}, u={3})' % tag),
+                        )
+                    )
                 except SanityError as e:
                     raise PerformanceError(e)
 
diff --git a/reframe/utility/sanity.py b/reframe/utility/sanity.py
index 687edd7abb..d6048c7d0d 100644
--- a/reframe/utility/sanity.py
+++ b/reframe/utility/sanity.py
@@ -514,7 +514,7 @@ def calc_bound(thres):
     try:
         evaluate(assert_bounded(val, lower, upper))
     except SanityError:
-        error_msg = '{0} is beyond reference value {1} (l={2}, u={3})'
+        error_msg = msg or '{0} is beyond reference value {1} (l={2}, u={3})'
         raise SanityError(_format(error_msg, val, ref, lower, upper))
     else:
         return True