diff --git a/src/util/mapbox.js b/src/util/mapbox.js
index eebe86194db..2619132f371 100644
--- a/src/util/mapbox.js
+++ b/src/util/mapbox.js
@@ -17,6 +17,10 @@ function makeAPIURL(urlObject: UrlObject, accessToken: string | null | void): st
     urlObject.protocol = apiUrlObject.protocol;
     urlObject.authority = apiUrlObject.authority;
 
+    if (apiUrlObject.path !== '/') {
+        urlObject.path = `${apiUrlObject.path}${urlObject.path}`;
+    }
+
     if (!config.REQUIRE_ACCESS_TOKEN) return formatUrl(urlObject);
 
     accessToken = accessToken || config.ACCESS_TOKEN;
diff --git a/test/unit/util/mapbox.test.js b/test/unit/util/mapbox.test.js
index ad08fb943a1..da8c5b4798c 100644
--- a/test/unit/util/mapbox.test.js
+++ b/test/unit/util/mapbox.test.js
@@ -30,6 +30,17 @@ test("mapbox", (t) => {
             t.end();
         });
 
+        t.test('handles custom API_URLs with paths', (t) => {
+            const previousUrl = config.API_URL;
+            config.API_URL = 'https://test.example.com/api.mapbox.com';
+            t.equal(
+                mapbox.normalizeStyleURL('mapbox://styles/foo/bar'),
+                'https://test.example.com/api.mapbox.com/styles/v1/foo/bar?access_token=key'
+            );
+            config.API_URL = previousUrl;
+            t.end();
+        });
+
         t.end();
     });
 
@@ -73,6 +84,17 @@ test("mapbox", (t) => {
             t.end();
         });
 
+        t.test('handles custom API_URLs with paths', (t) => {
+            const previousUrl = config.API_URL;
+            config.API_URL = 'https://test.example.com/api.mapbox.com';
+            t.equal(
+                mapbox.normalizeSourceURL('mapbox://one.a'),
+                'https://test.example.com/api.mapbox.com/v4/one.a.json?secure&access_token=key'
+            );
+            config.API_URL = previousUrl;
+            t.end();
+        });
+
         t.end();
     });
 
@@ -92,6 +114,17 @@ test("mapbox", (t) => {
             t.end();
         });
 
+        t.test('handles custom API_URLs with paths', (t) => {
+            const previousUrl = config.API_URL;
+            config.API_URL = 'https://test.example.com/api.mapbox.com';
+            t.equal(
+                mapbox.normalizeGlyphsURL('mapbox://fonts/boxmap/{fontstack}/{range}.pbf'),
+                'https://test.example.com/api.mapbox.com/fonts/v1/boxmap/{fontstack}/{range}.pbf?access_token=key'
+            );
+            config.API_URL = previousUrl;
+            t.end();
+        });
+
         t.end();
     });
 
@@ -149,6 +182,17 @@ test("mapbox", (t) => {
             t.end();
         });
 
+        t.test('handles custom API_URLs with paths', (t) => {
+            const previousUrl = config.API_URL;
+            config.API_URL = 'https://test.example.com/api.mapbox.com';
+            t.equal(
+                mapbox.normalizeSpriteURL('mapbox://sprites/mapbox/streets-v8', '', '.json'),
+                'https://test.example.com/api.mapbox.com/styles/v1/mapbox/streets-v8/sprite.json?access_token=key'
+            );
+            config.API_URL = previousUrl;
+            t.end();
+        });
+
         t.end();
     });