diff --git a/pkgs/development/compilers/mono/generic.nix b/pkgs/development/compilers/mono/generic.nix
index b84d8a6f574f..56547ece52e6 100644
--- a/pkgs/development/compilers/mono/generic.nix
+++ b/pkgs/development/compilers/mono/generic.nix
@@ -85,7 +85,7 @@ stdenv.mkDerivation rec {
   # Patch all the necessary scripts
   preBuild = ''
     makeFlagsArray=(INSTALL=`type -tp install`)
-    substituteInPlace mcs/class/corlib/System/Environment.cs --replace /usr/share "$out/share"
+    substituteInPlace mcs/class/corlib/System/Environment.cs --replace-fail /usr/share "$out/share"
   '';
 
   # Fix mono DLLMap so it can find libX11 to run winforms apps