diff --git a/builtin/push.c b/builtin/push.c
index 08ccb891c6..9a0a035629 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -147,12 +147,37 @@ static void setup_push_upstream(struct remote *remote, int simple)
 	add_refspec(refspec.buf);
 }
 
+static char warn_unspecified_push_default_msg[] =
+N_("push.default is unset; its implicit value is changing in\n"
+   "Git 2.0 from 'matching' to 'simple'. To squelch this message\n"
+   "and maintain the current behavior after the default changes, use:\n"
+   "\n"
+   "  git config --global push.default matching\n"
+   "\n"
+   "To squelch this message and adopt the new behavior now, use:\n"
+   "\n"
+   "  git config --global push.default simple\n"
+   "\n"
+   "See 'git help config' and search for 'push.default' for further information.\n"
+   "(the 'simple' mode was introduced in Git 1.7.11. Use the similar mode\n"
+   "'current' instead of 'simple' if you sometimes use older versions of Git)");
+
+static void warn_unspecified_push_default_configuration(void)
+{
+	static int warn_once;
+
+	if (warn_once++)
+		return;
+	warning("%s\n", _(warn_unspecified_push_default_msg));
+}
+
 static void setup_default_push_refspecs(struct remote *remote)
 {
 	switch (push_default) {
 	default:
 	case PUSH_DEFAULT_UNSPECIFIED:
 		default_matching_used = 1;
+		warn_unspecified_push_default_configuration();
 		/* fallthru */
 	case PUSH_DEFAULT_MATCHING:
 		add_refspec(":");
@@ -186,8 +211,8 @@ static const char message_advice_pull_before_push[] =
 static const char message_advice_use_upstream[] =
 	N_("Updates were rejected because a pushed branch tip is behind its remote\n"
 	   "counterpart. If you did not intend to push that branch, you may want to\n"
-	   "specify branches to push or set the 'push.default' configuration\n"
-	   "variable to 'current' or 'upstream' to push only the current branch.");
+	   "specify branches to push or set the 'push.default' configuration variable\n"
+	   "to 'simple', 'current' or 'upstream' to push only the current branch.");
 
 static const char message_advice_checkout_pull_push[] =
 	N_("Updates were rejected because a pushed branch tip is behind its remote\n"
diff --git a/t/t5541-http-push.sh b/t/t5541-http-push.sh
index 5b170be2c0..07fa199b14 100755
--- a/t/t5541-http-push.sh
+++ b/t/t5541-http-push.sh
@@ -64,7 +64,10 @@ test_expect_success 'no empty path components' '
 
 test_expect_success 'clone remote repository' '
 	rm -rf test_repo_clone &&
-	git clone $HTTPD_URL/smart/test_repo.git test_repo_clone
+	git clone $HTTPD_URL/smart/test_repo.git test_repo_clone &&
+	(
+		cd test_repo_clone && git config push.default matching
+	)
 '
 
 test_expect_success 'push to remote repository (standard)' '