1 files changed, 11 insertions, 1 deletions
diff --git a/toolkit/content/aboutNetError.mjs b/toolkit/content/aboutNetError.mjs
index 83f40fc479..554553fd62 100644
--- a/toolkit/content/aboutNetError.mjs
+++ b/toolkit/content/aboutNetError.mjs
@@ -430,11 +430,21 @@ function initPage() {
       tryAgain.hidden = true;
       break;
 
-    // Pinning errors are of type nssFailure2
+    // TLS errors and non-overridable certificate errors (e.g. pinning
+    // failures) are of type nssFailure2.
     case "nssFailure2": {
       learnMore.hidden = false;
 
       const errorCode = document.getNetErrorInfo().errorCodeString;
+      RPMRecordTelemetryEvent(
+        "security.ui.tlserror",
+        "load",
+        "abouttlserror",
+        errorCode,
+        {
+          is_frame: (window.parent != window).toString(),
+        }
+      );
       switch (errorCode) {
         case "SSL_ERROR_UNSUPPORTED_VERSION":
         case "SSL_ERROR_PROTOCOL_VERSION_ALERT": {