diff --git a/meta/classes-recipe/externalsrc.bbclass b/meta/classes-recipe/externalsrc.bbclass
index ce753fce76..06a9548a20 100644
--- a/meta/classes-recipe/externalsrc.bbclass
+++ b/meta/classes-recipe/externalsrc.bbclass
@@ -230,15 +230,16 @@ def srctree_hash_files(d, srcdir=None):
             env['GIT_INDEX_FILE'] = tmp_index.name
             subprocess.check_output(['git', 'add', '-A', '.'], cwd=s_dir, env=env)
             git_sha1 = subprocess.check_output(['git', 'write-tree'], cwd=s_dir, env=env).decode("utf-8")
-            submodule_helper = subprocess.check_output(['git', 'submodule--helper', 'list'], cwd=s_dir, env=env).decode("utf-8")
-            for line in submodule_helper.splitlines():
-                module_dir = os.path.join(s_dir, line.rsplit(maxsplit=1)[1])
-                if os.path.isdir(module_dir):
-                    proc = subprocess.Popen(['git', 'add', '-A', '.'], cwd=module_dir, env=env, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
-                    proc.communicate()
-                    proc = subprocess.Popen(['git', 'write-tree'], cwd=module_dir, env=env, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
-                    stdout, _ = proc.communicate()
-                    git_sha1 += stdout.decode("utf-8")
+            if os.path.exists(".gitmodules"):
+                submodule_helper = subprocess.check_output(["git", "config", "--file", ".gitmodules", "--get-regexp", "path"], cwd=s_dir, env=env).decode("utf-8")
+                for line in submodule_helper.splitlines():
+                    module_dir = os.path.join(s_dir, line.rsplit(maxsplit=1)[1])
+                    if os.path.isdir(module_dir):
+                        proc = subprocess.Popen(['git', 'add', '-A', '.'], cwd=module_dir, env=env, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+                        proc.communicate()
+                        proc = subprocess.Popen(['git', 'write-tree'], cwd=module_dir, env=env, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL)
+                        stdout, _ = proc.communicate()
+                        git_sha1 += stdout.decode("utf-8")
             sha1 = hashlib.sha1(git_sha1.encode("utf-8")).hexdigest()
         with open(oe_hash_file, 'w') as fobj:
             fobj.write(sha1)