diff --git a/http-streams.cabal b/http-streams.cabal
--- a/http-streams.cabal
+++ b/http-streams.cabal
@@ -1,6 +1,6 @@
 cabal-version:       >= 1.10
 name:                http-streams
-version:             0.7.2.4
+version:             0.7.2.5
 synopsis:            An HTTP client using io-streams
 description:
  /Overview/
diff --git a/lib/Network/Http/Inconvenience.hs b/lib/Network/Http/Inconvenience.hs
--- a/lib/Network/Http/Inconvenience.hs
+++ b/lib/Network/Http/Inconvenience.hs
@@ -126,7 +126,7 @@
     f c | c >= 'A' && c <= 'Z' = True
         | c >= 'a' && c <= 'z' = True
         | c >= '0' && c <= '9' = True
-    f c = c `elem` "$-_.!~*'(),"
+    f c = c `elem` ("$-_.!~*'(),"::String)
 
 
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