diff --git a/index.js b/index.js
index d6c45f9..1f3d982 100644
--- a/index.js
+++ b/index.js
@@ -186,7 +186,7 @@ function tokensToFunction (tokens) {
 
       if (token.optional) {
         // Prepend partial segment prefixes.
-        if (token.partial) path += token.prefix
+        if (i === 0 && token.partial) path += token.prefix
 
         continue
       }
@@ -323,7 +323,7 @@ function tokensToRegExp (tokens, keys, options) {
       if (keys) keys.push(token)
 
       if (token.optional) {
-        if (token.partial) {
+        if (i === 0 && token.partial) {
           route += escapeString(token.prefix) + '(' + capture + ')?'
         } else {
           route += '(?:' + escapeString(token.prefix) + '(' + capture + '))?'
diff --git a/test.ts b/test.ts
index 6cee055..4c8aab7 100644
--- a/test.ts
+++ b/test.ts
@@ -857,6 +857,40 @@ var TESTS: Test[] = [
       [{ test: 'foo' }, '/foo-bar']
     ]
   ],
+  [
+    '/:required/:optional?-ext',
+    null,
+    [
+      {
+        name: 'required',
+        prefix: '/',
+        delimiter: '/',
+        optional: false,
+        repeat: false,
+        partial: false,
+        pattern: '[^\\/]+?'
+      },
+      {
+        name: 'optional',
+        prefix: '/',
+        delimiter: '/',
+        optional: true,
+        repeat: false,
+        partial: true,
+        pattern: '[^\\/]+?'
+      },
+      '-ext'
+    ],
+    [
+      ['/foo-ext', ['/foo-ext', 'foo', undefined]],
+      ['/foo/bar-ext', ['/foo/bar-ext', 'foo', 'bar']],
+      ['/foo/-ext', null]
+    ],
+    [
+      [{ required: 'foo' }, '/foo-ext'],
+      [{ required: 'foo', optional: 'baz' }, '/foo/baz-ext']
+    ]
+  ],
   [
     '/:test*-bar',
     null,