diff --git a/src/router.zig b/src/router.zig
index 793700cf67..7e9ab9355e 100644
--- a/src/router.zig
+++ b/src/router.zig
@@ -1203,7 +1203,7 @@ const Pattern = struct {
     /// `null` means invalid. Error messages are logged.
     /// That way, we can provide a list of all invalid routes rather than failing the first time.
     pub fn validate(input: string, allocator: std.mem.Allocator, log: *Logger.Log) ?ValidationResult {
-        if (bun.strings.isAllASCII(input)) {
+        if (!bun.strings.isAllASCII(input)) {
             const source = Logger.Source.initEmptyFile(input);
             log.addErrorFmt(
                 &source,