diff --git a/cli/errors.rs b/cli/errors.rs
index 29fd428c86..b631f1b71c 100644
--- a/cli/errors.rs
+++ b/cli/errors.rs
@@ -32,6 +32,12 @@ pub(crate) fn get_error_class_name(e: &AnyError) -> &'static str {
         .map(get_diagnostic_class)
     })
     .unwrap_or_else(|| {
-      panic!("Error '{}' contains boxed error of unknown type", e);
+      panic!(
+        "Error '{}' contains boxed error of unknown type:{}",
+        e,
+        e.chain()
+          .map(|e| format!("\n  {:?}", e))
+          .collect::<String>()
+      );
     })
 }
diff --git a/cli/standalone.rs b/cli/standalone.rs
index a4b55f0812..48a4a28b3f 100644
--- a/cli/standalone.rs
+++ b/cli/standalone.rs
@@ -201,6 +201,12 @@ pub async fn run(
 
 fn get_error_class_name(e: &AnyError) -> &'static str {
   deno_runtime::errors::get_error_class_name(e).unwrap_or_else(|| {
-    panic!("Error '{}' contains boxed error of unknown type", e);
+    panic!(
+      "Error '{}' contains boxed error of unsupported type:{}",
+      e,
+      e.chain()
+        .map(|e| format!("\n  {:?}", e))
+        .collect::<String>()
+    );
   })
 }