diff --git a/tools/js2c.py b/tools/js2c.py
index eff44940c57ec6..d255010ad011fc 100755
--- a/tools/js2c.py
+++ b/tools/js2c.py
@@ -149,7 +149,7 @@ def ReadMacros(lines):
     hash = line.find('#')
     if hash != -1: line = line[:hash]
     line = line.strip()
-    if len(line) is 0: continue
+    if len(line) == 0: continue
     const_match = CONST_PATTERN.match(line)
     if const_match:
       name = const_match.group(1)
diff --git a/tools/test.py b/tools/test.py
index cb501637b8d524..19db5fdeaec41a 100755
--- a/tools/test.py
+++ b/tools/test.py
@@ -355,7 +355,7 @@ def HasRun(self, output):
     logger.info('  ---')
     logger.info('  duration_ms: %d.%d' %
       (total_seconds, duration.microseconds / 1000))
-    if self.severity is not 'ok' or self.traceback is not '':
+    if self.severity != 'ok' or self.traceback != '':
       if output.HasTimedOut():
         self.traceback = 'timeout\n' + output.output.stdout + output.output.stderr
       self._printDiagnostic()
@@ -1641,7 +1641,7 @@ def Main():
           continue
         archEngineContext = Execute([vm, "-p", "process.arch"], context)
         vmArch = archEngineContext.stdout.rstrip()
-        if archEngineContext.exit_code is not 0 or vmArch == "undefined":
+        if archEngineContext.exit_code != 0 or vmArch == "undefined":
           print("Can't determine the arch of: '%s'" % vm)
           print(archEngineContext.stderr.rstrip())
           continue