diff --git a/tools/test.py b/tools/test.py
index 8e323dfdd3455b..efb2ed7f3ce4ef 100755
--- a/tools/test.py
+++ b/tools/test.py
@@ -729,8 +729,8 @@ def GetTestStatus(self, context, sections, defs):
     'debug'   : ['--enable-slow-asserts', '--debug-code', '--verify-heap'],
     'release' : []}
 TIMEOUT_SCALEFACTOR = {
-    'debug'   : 4,
-    'release' : 1 }
+    'arm'  : { 'debug' : 8, 'release' : 2 },  # The ARM buildbots are slow.
+    'ia32' : { 'debug' : 4, 'release' : 1 } }
 
 
 class Context(object):
@@ -770,7 +770,7 @@ def GetVmFlags(self, testcase, mode):
     return testcase.variant_flags + FLAGS[mode]
 
   def GetTimeout(self, mode):
-    return self.timeout * TIMEOUT_SCALEFACTOR[mode]
+    return self.timeout * TIMEOUT_SCALEFACTOR[ARCH_GUESS or 'ia32'][mode]
 
 def RunTestCases(cases_to_run, progress, tasks):
   progress = PROGRESS_INDICATORS[progress](cases_to_run)
diff --git a/tools/utils.py b/tools/utils.py
index 232314cdee1076..2b312a2e103d08 100644
--- a/tools/utils.py
+++ b/tools/utils.py
@@ -73,7 +73,7 @@ def GuessOS():
 def GuessArchitecture():
   id = platform.machine()
   id = id.lower()  # Windows 7 capitalizes 'AMD64'.
-  if id.startswith('arm'):
+  if id.startswith('arm') or id == 'aarch64':
     return 'arm'
   elif (not id) or (not re.match('(x|i[3-6])86$', id) is None):
     return 'ia32'