diff --git a/config.c b/config.c
index f758734d45..d5bb8629a9 100644
--- a/config.c
+++ b/config.c
@@ -1120,11 +1120,16 @@ int git_config_parse_key(const char *key, char **store_key, int *baselen_)
 	 * key name separated by a dot, we have to know where the dot is.
 	 */
 
-	if (last_dot == NULL) {
+	if (last_dot == NULL || last_dot == key) {
 		error("key does not contain a section: %s", key);
 		return -2;
 	}
 
+	if (!last_dot[1]) {
+		error("key does not contain variable name: %s", key);
+		return -2;
+	}
+
 	baselen = last_dot - key;
 	if (baselen_)
 		*baselen_ = baselen;
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index c3d91d10a0..53fb8228cf 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -889,6 +889,10 @@ test_expect_success 'key sanity-checking' '
 	test_must_fail git config foo.1bar &&
 	test_must_fail git config foo."ba
 				z".bar &&
+	test_must_fail git config . false &&
+	test_must_fail git config .foo false &&
+	test_must_fail git config foo. false &&
+	test_must_fail git config .foo. false &&
 	git config foo.bar true &&
 	git config foo."ba =z".bar false
 '