diff --git a/tools/proguard.py b/tools/proguard.py
index efcf560..640094f 100755
--- a/tools/proguard.py
+++ b/tools/proguard.py
@@ -15,14 +15,14 @@
 PROGUARD_JAR = os.path.join(utils.REPO_ROOT, 'third_party', 'proguard',
     'proguard_internal_159423826', 'ProGuard_deploy.jar')
 
-def run(args, track_memory_file = None):
+def run(args, track_memory_file = None, stdout=None, stderr=None):
   cmd = []
   if track_memory_file:
     cmd.extend(['tools/track_memory.sh', track_memory_file])
   cmd.extend(['java', '-jar', PROGUARD_JAR])
   cmd.extend(args)
   utils.PrintCmd(cmd)
-  subprocess.check_call(cmd)
+  subprocess.call(cmd, stdout=stdout, stderr=stderr)
 
 def Main():
   run(sys.argv[1:])
diff --git a/tools/run_proguard_dx_on_app.py b/tools/run_proguard_dx_on_app.py
index a953229..4624f26 100755
--- a/tools/run_proguard_dx_on_app.py
+++ b/tools/run_proguard_dx_on_app.py
@@ -115,7 +115,10 @@
     track_memory_file = None
     if options.print_memoryuse:
       track_memory_file = join(temp, utils.MEMORY_USE_TMP_FILE)
-    proguard.run(args, track_memory_file = track_memory_file)
+    proguard.run(
+        args,
+        track_memory_file = track_memory_file,
+        stdout=open(os.devnull, 'w'))
     if options.print_memoryuse:
       proguard_memoryuse = utils.grep_memoryuse(track_memory_file)