diff --git a/ghc-happstack-server.spec b/ghc-happstack-server.spec
index 2b2ddb6..6609b18 100644
--- a/ghc-happstack-server.spec
+++ b/ghc-happstack-server.spec
@@ -33,7 +33,7 @@ BuildRequires:  ghc-monad-control-devel
 BuildRequires:  ghc-sendfile-devel
 BuildRequires:  ghc-syb-devel
 BuildRequires:  ghc-template-haskell-devel
-BuildRequires:  ghc-utf8-string-devel
+BuildRequires:  ghc-utf8-string-prof
 BuildRequires:  ghc-xhtml-devel
 BuildRequires:  ghc-zlib-devel
 Patch1:         happstack-server-default-to-base4.patch