diff --git a/src/TmpFile.php b/src/TmpFile.php
index <HASH>..<HASH> 100644
--- a/src/TmpFile.php
+++ b/src/TmpFile.php
@@ -18,7 +18,7 @@ final class TmpFile implements TmpFileInterface
         $this->filename = tempnam(sys_get_temp_dir(), 'php');
 
         if (false === $this->filename) {
-            throw new \RuntimeException("tempnam() couldn't create a temp file");
+            throw new \RuntimeException('tempnam() could not create a temp file');
         }
 
         $this->handler = static function (string $filename) {
@@ -30,6 +30,11 @@ final class TmpFile implements TmpFileInterface
         register_shutdown_function($this->handler, $this->filename);
     }
 
+    public function getFilename(): string
+    {
+        return $this->filename;
+    }
+
     public function __toString(): string
     {
         return $this->filename;
diff --git a/src/TmpFileInterface.php b/src/TmpFileInterface.php
index <HASH>..<HASH> 100644
--- a/src/TmpFileInterface.php
+++ b/src/TmpFileInterface.php
@@ -4,8 +4,7 @@ namespace TmpFile;
 
 interface TmpFileInterface
 {
-    /**
-     * @return string Should return the filename of a temp file on disk
-     */
+    public function getFilename(): string;
+
     public function __toString(): string;
 }
Added getFilename() method to TmpFile