diff --git a/src/Records/RData.php b/src/Records/RData.php
index 3c71546..d95f3d0 100644
--- a/src/Records/RData.php
+++ b/src/Records/RData.php
@@ -55,7 +55,7 @@ public function __toString()
         if ($handler = $this->typeDef->getToStringFunction()) {
             $result = \call_user_func_array($handler, $this->fields);
         } else {
-            $result = \implode(',', $this->fields);
+            $result = \implode('', $this->fields);
         }
 
         return $result;