diff --git a/http-walker.c b/http-walker.c
index 1b6d496548..f252de089f 100644
--- a/http-walker.c
+++ b/http-walker.c
@@ -268,7 +268,7 @@ static void process_alternates_response(void *callback_data)
 				 */
 				const char *colon_ss = strstr(base,"://");
 				if (colon_ss) {
-					serverlen = (strchr(colon_ss + 3, '/')
+					serverlen = (strchrnul(colon_ss + 3, '/')
 						     - base);
 					okay = 1;
 				}
diff --git a/t/t5550-http-fetch-dumb.sh b/t/t5550-http-fetch-dumb.sh
index 9d0a7f5c4b..b0080bf204 100755
--- a/t/t5550-http-fetch-dumb.sh
+++ b/t/t5550-http-fetch-dumb.sh
@@ -555,4 +555,24 @@ test_expect_success 'dumb http can fetch index v1' '
 	git -C idx-v1 fsck
 '
 
+test_expect_success 'absolute-path alternate when url has no path' '
+	src=$HTTPD_DOCUMENT_ROOT_PATH/repo.git &&
+	alt=absolute-alt.git &&
+	git clone --bare --shared "$src" "$alt" &&
+
+	# Our repo has an alternate pointing to the absolute filesystem path,
+	# but that will not make any sense to an http client. So we will
+	# manually give it the equivalent path that the http server will
+	# understand.
+	echo "/dumb/repo.git/objects" >"$alt/objects/info/http-alternates" &&
+
+	# Now make our alt repository available at the root of the http
+	# server without any path (i.e., just http://localhost:1234).
+	git -C "$alt" update-server-info &&
+	mv absolute-alt.git/* "$HTTPD_DOCUMENT_ROOT_PATH" &&
+
+	git -c http.followRedirects=true clone "$HTTPD_URL" alt-clone.git 2>err &&
+	test_grep "adding alternate object store: $HTTPD_URL/dumb/repo.git" err
+'
+
 test_done