diff --git a/testing/mochitest/runtests.py.in b/testing/mochitest/runtests.py.in
index 542c697e7ff..711febbb457 100644
--- a/testing/mochitest/runtests.py.in
+++ b/testing/mochitest/runtests.py.in
@@ -365,19 +365,25 @@ Are you executing $objdir/_tests/testing/mochitest/runtests.py?"""
   if not os.path.exists(LEAK_REPORT_FILE):
     log.info("WARNING refcount logging is off, so leaks can't be detected!")
   else:
-    leaks = open(LEAK_REPORT_FILE, "r")
-    for line in leaks:
-      log.info(line.rstrip())
-    leaks.close()
-
-    threshold = options.leakThreshold
-    leaks = open(LEAK_REPORT_FILE, "r")
     #                  Per-Inst  Leaked      Total  Rem ...
     #   0 TOTAL              17     192  419115886    2 ...
     # 833 nsTimerImpl        60     120      24726    2 ...
     lineRe = re.compile(r"^\s*\d+\s+(?P<name>\S+)\s+"
                         r"(?P<size>-?\d+)\s+(?P<bytesLeaked>-?\d+)\s+"
                         r"\d+\s+(?P<numLeaked>-?\d+)")
+
+    leaks = open(LEAK_REPORT_FILE, "r")
+    for line in leaks:
+      matches = lineRe.match(line)
+      if (matches and
+          int(matches.group("numLeaked")) == 0 and
+          matches.group("name") != "TOTAL"):
+        continue
+      log.info(line.rstrip())
+    leaks.close()
+
+    threshold = options.leakThreshold
+    leaks = open(LEAK_REPORT_FILE, "r")
     seenTotal = False
     prefix = "TEST-PASS"
     for line in leaks: