diff --git a/pkgs/development/ruby-modules/gem-config/default.nix b/pkgs/development/ruby-modules/gem-config/default.nix
index 6ae3c824a4e..8da6355e001 100644
--- a/pkgs/development/ruby-modules/gem-config/default.nix
+++ b/pkgs/development/ruby-modules/gem-config/default.nix
@@ -92,7 +92,7 @@ in
     dontBuild = false;
     postPatch = ''
       substituteInPlace lib/ethon/curls/settings.rb \
-        --replace "libcurl" "${curl.out}/lib/libcurl.so"
+        --replace "libcurl" "${curl.out}/lib/libcurl${stdenv.hostPlatform.extensions.sharedLibrary}"
     '';
   };