diff --git a/dom/system/gonk/ril_worker.js b/dom/system/gonk/ril_worker.js
index 534f3b347e66..92df155b4c3d 100644
--- a/dom/system/gonk/ril_worker.js
+++ b/dom/system/gonk/ril_worker.js
@@ -8742,10 +8742,12 @@ let ICCIOHelper = {
     // description.
     let errorMsg = "ICC I/O Error code " +
                    RIL_ERROR_TO_GECKO_ERROR[options.rilRequestError] +
-                   "EF id = " + options.fileId.toString(16) +
-                   " command = " + options.command.toString(16) +
-                   "(" + options.sw1.toString(16) +
-                   "/" + options.sw2.toString(16) + ")";
+                   " EF id = " + options.fileId.toString(16) +
+                   " command = " + options.command.toString(16);
+    if (options.sw1 && options.sw2) {
+      errorMsg += "(" + options.sw1.toString(16) +
+                  "/" + options.sw2.toString(16) + ")";
+    }
     error(errorMsg);
   },
 };