diff --git a/Spock-core/src/Web/Spock/Core.hs b/Spock-core/src/Web/Spock/Core.hs
index 2058077..2be669a 100644
--- a/Spock-core/src/Web/Spock/Core.hs
+++ b/Spock-core/src/Web/Spock/Core.hs
@@ -68,6 +68,7 @@ module Web.Spock.Core
 where
 
 import Control.Applicative
+import Control.Monad
 import Control.Monad.Reader
 import Data.Foldable (forM_)
 import Data.HVect hiding (head)
diff --git a/stack.yaml b/stack.yaml
index 452b508..aa8433d 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -15,6 +15,7 @@ extra-deps:
   - superbuffer-0.3.1.2
 
   - regex-posix-clib-2.7
+allow-newer: true
 
 flags:
   regex-posix: