diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index 41340c7..9e30644 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -200,10 +200,14 @@
         additional_pg_conf = GenerateAdditionalProguardConfiguration(
             temp, os.path.abspath(pg_outdir))
         args.extend(['--pg-conf', additional_pg_conf])
-      toolhelper.run(options.compiler, args, build=not options.no_build,
+      exit_code = toolhelper.run(options.compiler, args,
+                     build=not options.no_build,
                      debug=not options.no_debug,
                      profile=options.profile,
                      track_memory_file=options.track_memory_to_file)
+      if exit_code != 0:
+        return exit_code
+
       if options.print_memoryuse:
         print('{}(MemoryUse): {}'
             .format(options.print_memoryuse,
diff --git a/tools/toolhelper.py b/tools/toolhelper.py
index 82a2824..dbf393b 100644
--- a/tools/toolhelper.py
+++ b/tools/toolhelper.py
@@ -3,9 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 import gradle
-import os
 import subprocess
-import sys
 import utils
 
 def run(tool, args, build=None, debug=True,