diff --git a/fsck.c b/fsck.c
index 135fe8c..3a65a3b 100644
--- a/fsck.c
+++ b/fsck.c
@@ -95,6 +95,7 @@
 	FUNC(GITMODULES_SYMLINK, ERROR) \
 	FUNC(GITMODULES_URL, ERROR) \
 	FUNC(GITMODULES_PATH, ERROR) \
+	FUNC(GITMODULES_UPDATE, ERROR) \
 	/* warnings */ \
 	FUNC(BAD_FILEMODE, WARN) \
 	FUNC(EMPTY_NAME, WARN) \
@@ -998,6 +999,11 @@
 				    FSCK_MSG_GITMODULES_PATH,
 				    "disallowed submodule path: %s",
 				    value);
+	if (!strcmp(key, "update") && value && *value == '!')
+		data->ret |= report(data->options, data->obj,
+				    FSCK_MSG_GITMODULES_UPDATE,
+				    "disallowed submodule update setting: %s",
+				    value);
 	free(name);
 
 	return 0;
diff --git a/t/t7406-submodule-update.sh b/t/t7406-submodule-update.sh
index 3781809..a74e7ea 100755
--- a/t/t7406-submodule-update.sh
+++ b/t/t7406-submodule-update.sh
@@ -397,6 +397,20 @@
 	git -C super submodule update submodule
 '
 
+test_expect_success 'fsck detects command in .gitmodules' '
+	git init command-in-gitmodules &&
+	(
+		cd command-in-gitmodules &&
+		git submodule add ../submodule submodule &&
+		test_commit adding-submodule &&
+
+		git config -f .gitmodules submodule.submodule.update "!false" &&
+		git add .gitmodules &&
+		test_commit configuring-update &&
+		test_must_fail git fsck
+	)
+'
+
 cat << EOF >expect
 Execution of 'false $submodulesha1' failed in submodule path 'submodule'
 EOF