diff --git a/src/errors/InternalError.ts b/src/errors/InternalError.ts
index 376caf6..400512f 100644
--- a/src/errors/InternalError.ts
+++ b/src/errors/InternalError.ts
@@ -29,5 +29,9 @@ export class InternalError<T = ErrorDetails> extends Error {
 
 export function isInternalError(error: unknown): error is InternalError {
   // biome-ignore lint/suspicious/noExplicitAny: checking for existence of prop outside or Error interface
-  return isError(error) && (error as any)[Symbol.for(INTERNAL_ERROR_SYMBOL_KEY)] === true
+  return (
+    isError(error) &&
+    ((error as any)[Symbol.for(INTERNAL_ERROR_SYMBOL_KEY)] === true ||
+      error.name === 'InternalError')
+  )
 }
diff --git a/src/errors/PublicNonRecoverableError.ts b/src/errors/PublicNonRecoverableError.ts
index 5640ddc..a7fd039 100644
--- a/src/errors/PublicNonRecoverableError.ts
+++ b/src/errors/PublicNonRecoverableError.ts
@@ -36,6 +36,8 @@ export class PublicNonRecoverableError<T = ErrorDetails> extends Error {
 export function isPublicNonRecoverableError(error: unknown): error is PublicNonRecoverableError {
   return (
     // biome-ignore lint/suspicious/noExplicitAny: checking for existence of prop outside or Error interface
-    isError(error) && (error as any)[Symbol.for(PUBLIC_NON_RECOVERABLE_ERROR_SYMBOL_KEY)] === true
+    isError(error) &&
+    ((error as any)[Symbol.for(PUBLIC_NON_RECOVERABLE_ERROR_SYMBOL_KEY)] === true ||
+      error.name === 'PublicNonRecoverableError')
   )
 }