diff --git a/client.mk b/client.mk
index 42133d2eb383..f2c606f2e6f2 100644
--- a/client.mk
+++ b/client.mk
@@ -329,6 +329,10 @@ CONFIG_STATUS_DEPS := \
   $(OBJDIR)/.mozconfig.json \
   $(NULL)
 
+# Include a dep file emitted by configure to track Python files that
+# may influence the result of configure.
+-include $(OBJDIR)/configure.d
+
 CONFIGURE_ENV_ARGS += \
   MAKE='$(MAKE)' \
   $(NULL)
diff --git a/configure.py b/configure.py
index f7392d0ffa5c..75470fb542b6 100644
--- a/configure.py
+++ b/configure.py
@@ -5,6 +5,7 @@
 from __future__ import print_function, unicode_literals
 
 import codecs
+import itertools
 import os
 import subprocess
 import sys
@@ -14,6 +15,8 @@ import textwrap
 base_dir = os.path.abspath(os.path.dirname(__file__))
 sys.path.insert(0, os.path.join(base_dir, 'python', 'mozbuild'))
 from mozbuild.configure import ConfigureSandbox
+from mozbuild.makeutil import Makefile
+from mozbuild.pythonutil import iter_modules_in_path
 from mozbuild.util import (
     indented_repr,
     encode,
@@ -46,7 +49,8 @@ def config_status(config):
     sanitized_config = {}
     sanitized_config['substs'] = {
         k: sanitized_bools(v) for k, v in config.iteritems()
-        if k not in ('DEFINES', 'non_global_defines', 'TOPSRCDIR', 'TOPOBJDIR')
+        if k not in ('DEFINES', 'non_global_defines', 'TOPSRCDIR', 'TOPOBJDIR',
+                     'ALL_CONFIGURE_PATHS')
     }
     sanitized_config['defines'] = {
         k: sanitized_bools(v) for k, v in config['DEFINES'].iteritems()
@@ -84,6 +88,17 @@ def config_status(config):
                     config_status(**args)
             '''))
 
+    # Write out a depfile so Make knows to re-run configure when relevant Python
+    # changes.
+    mk = Makefile()
+    rule = mk.create_rule()
+    rule.add_targets(["$(OBJDIR)/config.status"])
+    rule.add_dependencies(itertools.chain(config['ALL_CONFIGURE_PATHS'],
+                                          iter_modules_in_path(config['TOPOBJDIR'],
+                                                               config['TOPSRCDIR'])))
+    with open('configure.d', 'w') as fh:
+        mk.dump(fh)
+
     # Other things than us are going to run this file, so we need to give it
     # executable permissions.
     os.chmod('config.status', 0o755)
diff --git a/moz.configure b/moz.configure
index ec90697f5d76..17fa353199f4 100644
--- a/moz.configure
+++ b/moz.configure
@@ -338,4 +338,10 @@ def nsis_binary_type(nsis):
 
 # Fallthrough to autoconf-based configure
 include('build/moz.configure/old.configure')
-# Please do not add anything after the include of old.configure.
+
+@imports('__sandbox__')
+def all_paths():
+    return __sandbox__._all_paths
+
+set_config('ALL_CONFIGURE_PATHS', all_paths())
+# Please do not add anything after setting ALL_CONFIGURE_PATHS.