diff --git a/ghc-formatting.spec b/ghc-formatting.spec
index e3555e4..3e5582a 100644
--- a/ghc-formatting.spec
+++ b/ghc-formatting.spec
@@ -99,7 +99,7 @@ dos2unix -k -n %{SOURCE1} %{pkg_name}.cabal
 # End cabal-rpm setup
 
 %ifarch ppc64le
-sed -e "s/ -rtsopts -with-rtsopts=-N//" %{pkg_name}.cabal
+sed -i -e "s/ -rtsopts -with-rtsopts=-N//" %{pkg_name}.cabal
 %endif