diff --git a/gclient.py b/gclient.py
index e1b1be2ff..8f1a48978 100755
--- a/gclient.py
+++ b/gclient.py
@@ -1825,9 +1825,7 @@ def _FlattenDep(dep, allowed_hosts, deps, deps_os, hooks, hooks_os,
 
   _AddDep(dep, allowed_hosts, deps, unpinned_deps)
 
-  for dep_os, os_deps in dep.os_dependencies.iteritems():
-    for os_dep in os_deps:
-      deps_os.setdefault(dep_os, {})[os_dep.name] = os_dep
+  _FlattenDepsOs(dep, deps_os)
 
   deps_by_name = dict((d.name, d) for d in dep.dependencies)
   for recurse_dep_name in (dep.recursedeps or []):
@@ -1860,11 +1858,29 @@ def _FlattenRecurse(dep, allowed_hosts, deps, deps_os, hooks, hooks_os,
   """
   logging.debug('_FlattenRecurse(%r)', dep)
 
+  _FlattenDepsOs(dep, deps_os)
+
   for sub_dep in dep.orig_dependencies:
     _FlattenDep(sub_dep, allowed_hosts, deps, deps_os, hooks, hooks_os,
                 pre_deps_hooks, unpinned_deps)
 
 
+def _FlattenDepsOs(dep, deps_os):
+  """Helper to add a dependency to flattened lists.
+
+  Arguments:
+    dep (Dependency): dependency to process
+
+  Out-parameters:
+    deps_os (dict): will be filled with flattened deps_os
+  """
+  logging.debug('_FlattenDepsOs(%r)', dep)
+
+  for dep_os, os_deps in dep.os_dependencies.iteritems():
+    for os_dep in os_deps:
+      deps_os.setdefault(dep_os, {})[os_dep.name] = os_dep
+
+
 def _AddDep(dep, allowed_hosts, deps, unpinned_deps):
   """Helper to add a dependency to flattened lists.
 
diff --git a/testing_support/fake_repos.py b/testing_support/fake_repos.py
index 7c912299d..4bc4e15b5 100755
--- a/testing_support/fake_repos.py
+++ b/testing_support/fake_repos.py
@@ -298,7 +298,7 @@ class FakeReposBase(object):
 
 class FakeRepos(FakeReposBase):
   """Implements populateGit()."""
-  NB_GIT_REPOS = 7
+  NB_GIT_REPOS = 8
 
   def populateGit(self):
     # Testing:
@@ -473,6 +473,7 @@ deps = {
     'url': '/repo_4',
     'condition': 'False',
   },
+  'src/repo8': '/repo_8',
 }
 deps_os ={
   'mac': {
@@ -513,6 +514,7 @@ hooks_os = {
 }
 recursedeps = [
   'src/repo2',
+  'src/repo8',
 ]""" % {
         'git_base': self.git_base,
         'hash': self.git_hashes['repo_2'][1][0][:7]
@@ -541,6 +543,19 @@ hooks = [
       'origin': 'git/repo_7@1\n',
     })
 
+    self._commit_git('repo_8', {
+      'DEPS': """
+deps_os ={
+  'mac': {
+    'src/recursed_os_repo': '/repo_5',
+  },
+  'unix': {
+    'src/recursed_os_repo': '/repo_5',
+  },
+}""",
+      'origin': 'git/repo_8@1\n',
+    })
+
 
 class FakeRepoSkiaDEPS(FakeReposBase):
   """Simulates the Skia DEPS transition in Chrome."""
diff --git a/tests/gclient_smoketest.py b/tests/gclient_smoketest.py
index 6e1f020fe..a13dad22e 100755
--- a/tests/gclient_smoketest.py
+++ b/tests/gclient_smoketest.py
@@ -609,6 +609,11 @@ class GClientSmokeGIT(GClientSmokeBase):
         '    "condition": "False",',
         '  },',
         '',
+        '  # src -> src/repo8',
+        '  "src/repo8": {',
+        '    "url": "/repo_8",',
+        '  },',
+        '',
         '}',
         '',
         'deps_os = {',
@@ -618,9 +623,19 @@ class GClientSmokeGIT(GClientSmokeBase):
         '      "url": "/repo_5",',
         '    },',
         '',
+        '    # src -> src/repo8 -> src/recursed_os_repo',
+        '    "src/recursed_os_repo": {',
+        '      "url": "/repo_5",',
+        '    },',
+        '',
         '  },',
         '',
         '  "unix": {',
+        '    # src -> src/repo8 -> src/recursed_os_repo',
+        '    "src/recursed_os_repo": {',
+        '      "url": "/repo_5",',
+        '    },',
+        '',
         '    # src -> src/unix_repo',
         '    "src/unix_repo": {',
         '      "url": "/repo_5",',