diff --git a/submodule-config.c b/submodule-config.c
index 93453909cf..3e8e380d98 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -234,6 +234,26 @@ int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg)
 	return parse_fetch_recurse(opt, arg, 1);
 }
 
+static int parse_update_recurse(const char *opt, const char *arg,
+				int die_on_error)
+{
+	switch (git_config_maybe_bool(opt, arg)) {
+	case 1:
+		return RECURSE_SUBMODULES_ON;
+	case 0:
+		return RECURSE_SUBMODULES_OFF;
+	default:
+		if (die_on_error)
+			die("bad %s argument: %s", opt, arg);
+		return RECURSE_SUBMODULES_ERROR;
+	}
+}
+
+int parse_update_recurse_submodules_arg(const char *opt, const char *arg)
+{
+	return parse_update_recurse(opt, arg, 1);
+}
+
 static int parse_push_recurse(const char *opt, const char *arg,
 			       int die_on_error)
 {
diff --git a/submodule-config.h b/submodule-config.h
index 70f19363fd..d434ecdb45 100644
--- a/submodule-config.h
+++ b/submodule-config.h
@@ -22,16 +22,17 @@ struct submodule {
 	int recommend_shallow;
 };
 
-int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
-int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
-int parse_submodule_config_option(const char *var, const char *value);
-const struct submodule *submodule_from_name(const unsigned char *commit_or_tree,
-		const char *name);
-const struct submodule *submodule_from_path(const unsigned char *commit_or_tree,
-		const char *path);
+extern int parse_fetch_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_update_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_push_recurse_submodules_arg(const char *opt, const char *arg);
+extern int parse_submodule_config_option(const char *var, const char *value);
+extern const struct submodule *submodule_from_name(
+		const unsigned char *commit_or_tree, const char *name);
+extern const struct submodule *submodule_from_path(
+		const unsigned char *commit_or_tree, const char *path);
 extern int gitmodule_sha1_from_commit(const unsigned char *commit_sha1,
 				      unsigned char *gitmodules_sha1,
 				      struct strbuf *rev);
-void submodule_free(void);
+extern void submodule_free(void);
 
 #endif /* SUBMODULE_CONFIG_H */