diff --git a/pkgs/applications/science/misc/foldingathome/control.nix b/pkgs/applications/science/misc/foldingathome/control.nix
index 1430881a3f08..e5cc02edcfbe 100644
--- a/pkgs/applications/science/misc/foldingathome/control.nix
+++ b/pkgs/applications/science/misc/foldingathome/control.nix
@@ -42,7 +42,7 @@ stdenv.mkDerivation rec {
   installPhase = "cp -ar usr $out";
 
   postFixup = ''
-    sed -e 's|/usr/bin|$out/bin|g' -i $out/share/applications/FAHControl.desktop
+    sed -e "s|/usr/bin|$out/bin|g" -i $out/share/applications/FAHControl.desktop
     wrapProgram "$out/bin/FAHControl" \
       --suffix PATH : "${fahviewer.outPath}/bin" \
       --set PYTHONPATH "$out/lib/python2.7/dist-packages"
diff --git a/pkgs/applications/science/misc/foldingathome/viewer.nix b/pkgs/applications/science/misc/foldingathome/viewer.nix
index 52ca9c9e623f..75e900a0a72c 100644
--- a/pkgs/applications/science/misc/foldingathome/viewer.nix
+++ b/pkgs/applications/science/misc/foldingathome/viewer.nix
@@ -38,7 +38,7 @@ stdenv.mkDerivation rec {
 
   unpackPhase = ''
     dpkg-deb -x ${src} ./
-    sed -e 's|/usr/bin|$out/bin|g' -i usr/share/applications/FAHViewer.desktop
+    sed -e "s|/usr/bin|$out/bin|g" -i usr/share/applications/FAHViewer.desktop
   '';
 
   installPhase = ''