diff --git a/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php b/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
--- a/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
+++ b/src/infrastructure/customfield/standard/PhabricatorStandardCustomField.php
@@ -301,10 +301,14 @@
   }
 
   public function renderPropertyViewValue(array $handles) {
-    if (!phutil_nonempty_string($this->getFieldValue())) {
+    // If your field needs to render anything more complicated then a string,
+    // then you should override this method.
+    $value_str = phutil_string_cast($this->getFieldValue());
+
+    if (!phutil_nonempty_string($value_str)) {
       return null;
     }
-    return $this->getFieldValue();
+    return $value_str;
   }
 
   public function shouldAppearInApplicationSearch() {