diff --git a/src/Purl/Fragment.php b/src/Purl/Fragment.php
index d973ecd..5b415d4 100644
--- a/src/Purl/Fragment.php
+++ b/src/Purl/Fragment.php
@@ -7,6 +7,8 @@
 use function array_merge;
 use function parse_url;
 use function sprintf;
+use function strpos;
+use function substr;
 
 /**
  * Fragment represents the part of a Url after the hashmark (#).
@@ -113,7 +115,17 @@ public function __toString() : string
     protected function doInitialize() : void
     {
         if ($this->fragment !== null) {
-            $this->data = array_merge($this->data, parse_url($this->fragment));
+            $pos   = strpos($this->fragment, ':', 1);
+            $colon = '';
+            if ($pos !== false) {
+                $colon = substr($this->fragment, $pos);
+            }
+            $data = parse_url($this->fragment);
+            if ($colon !== '') {
+                $data = ['path' => $this->fragment];
+            }
+
+            $this->data = array_merge($this->data, $data);
         }
 
         foreach ($this->data as $key => $value) {
diff --git a/tests/Purl/Test/UrlTest.php b/tests/Purl/Test/UrlTest.php
index 6344756..6fe671b 100644
--- a/tests/Purl/Test/UrlTest.php
+++ b/tests/Purl/Test/UrlTest.php
@@ -362,6 +362,10 @@ public function testRelativeUrl() : void
         $url = new Url('/events');
         $url->query->set('param1', 'value1');
         $this->assertEquals('/events?param1=value1', (string) $url);
+
+        // test fragment with colon
+        $url = new Url('http://example.com/#hello:123');
+        $this->assertEquals('http://example.com/#hello:123', (string) $url);
     }
 }