diff --git a/servant-server/servant-server.cabal b/servant-server/servant-server.cabal
index 0bfba00a..b4a83df3 100644
--- a/servant-server/servant-server.cabal
+++ b/servant-server/servant-server.cabal
@@ -51,7 +51,7 @@ library
       , safe               >= 0.3  && < 0.4
       , servant            == 0.4.*
       , split              >= 0.2  && < 0.3
-      , string-conversions >= 0.3  && < 0.4
+      , string-conversions >= 0.3  && < 0.5
       , system-filepath    >= 0.4  && < 0.5
       , filepath           >= 1
       , text               >= 1.2  && < 1.3
diff --git a/servant/servant.cabal b/servant/servant.cabal
index 81b476cd..fb605e11 100644
--- a/servant/servant.cabal
+++ b/servant/servant.cabal
@@ -55,7 +55,7 @@ library
     , http-media >= 0.4 && < 0.7
     , http-types == 0.8.*
     , text >= 1 && < 2
-    , string-conversions >= 0.3 && < 0.4
+    , string-conversions >= 0.3 && < 0.5
     , network-uri >= 2.6
   hs-source-dirs: src
   default-language: Haskell2010