1 files changed, 9 insertions, 0 deletions
diff --git a/devtools/client/debugger/src/utils/source.js b/devtools/client/debugger/src/utils/source.js
index 91a02778e2..1a2b453ec2 100644
--- a/devtools/client/debugger/src/utils/source.js
+++ b/devtools/client/debugger/src/utils/source.js
@@ -209,6 +209,15 @@ function resolveFileURL(
 }
 
 export function getFormattedSourceId(id) {
+  if (typeof id != "string") {
+    console.error(
+      "Expected source id to be a string, got",
+      typeof id,
+      " | id:",
+      id
+    );
+    return "";
+  }
   return id.substring(id.lastIndexOf("/") + 1);
 }