diff --git a/pkgs/development/compilers/ghc/8.4.3.nix b/pkgs/development/compilers/ghc/8.4.3.nix
index 4d2f3894f17..10035af90a8 100644
--- a/pkgs/development/compilers/ghc/8.4.3.nix
+++ b/pkgs/development/compilers/ghc/8.4.3.nix
@@ -49,7 +49,8 @@ let
   '' + stdenv.lib.optionalString enableIntegerSimple ''
     INTEGER_LIBRARY = integer-simple
   '' + stdenv.lib.optionalString (targetPlatform != hostPlatform) ''
-    Stage1Only = YES
+    Stage1Only = ${if targetPlatform.system == hostPlatform.system then "NO" else "YES"}
+    CrossCompilePrefix = ${targetPrefix}
     HADDOCK_DOCS = NO
     BUILD_SPHINX_HTML = NO
     BUILD_SPHINX_PDF = NO