diff --git a/changelog/unreleased/issue-4085 b/changelog/unreleased/issue-4085
new file mode 100644
index 000000000..f8dba293a
--- /dev/null
+++ b/changelog/unreleased/issue-4085
@@ -0,0 +1 @@
+Fix error code in function isAccessDenied.
\ No newline at end of file
diff --git a/internal/backend/s3/s3.go b/internal/backend/s3/s3.go
index 58ae65f97..ad652a206 100644
--- a/internal/backend/s3/s3.go
+++ b/internal/backend/s3/s3.go
@@ -164,7 +164,7 @@ func isAccessDenied(err error) bool {
 	debug.Log("isAccessDenied(%T, %#v)", err, err)
 
 	var e minio.ErrorResponse
-	return errors.As(err, &e) && e.Code == "Access Denied"
+	return errors.As(err, &e) && e.Code == "AccessDenied"
 }
 
 // IsNotExist returns true if the error is caused by a not existing file.