diff --git a/packages/flutter_tools/pubspec.yaml b/packages/flutter_tools/pubspec.yaml
index 63e2d8a41db..69e483142a0 100644
--- a/packages/flutter_tools/pubspec.yaml
+++ b/packages/flutter_tools/pubspec.yaml
@@ -12,7 +12,7 @@ dependencies:
   args: ^0.13.0
   asn1lib: ^0.4.1
   cipher: ^0.7.1
-  flx: ">=0.0.1"
+  flx: ">=0.0.1 <0.1.0"
   crypto: ^0.9.1
   mustache4dart: ^1.0.0
   path: ^1.3.0