diff --git a/envy.cabal b/envy.cabal
--- a/envy.cabal
+++ b/envy.cabal
@@ -1,5 +1,5 @@
 name:                envy
-version:             2.1.4.0
+version:             2.1.5.0
 synopsis:            An environmentally friendly way to deal with environment variables
 license:             BSD3
 license-file:        LICENSE
@@ -22,7 +22,7 @@
   hs-source-dirs:       src
   build-depends:        base         >= 4.11 && < 5
                       , bytestring   >= 0.10 && < 0.13
-                      , containers   >= 0.5 && < 0.8
+                      , containers   >= 0.5 && < 0.9
                       , mtl          == 2.2.* || == 2.3.*
                       , text         == 1.2.* || >= 2.0 && <2.2
                       , time         >= 1.5 && < 2.0