diff --git a/pkgs/development/libraries/libgit2/default.nix b/pkgs/development/libraries/libgit2/default.nix
index c0e3ab0aca40..35b3fef3087d 100644
--- a/pkgs/development/libraries/libgit2/default.nix
+++ b/pkgs/development/libraries/libgit2/default.nix
@@ -27,7 +27,6 @@ stdenv.mkDerivation rec {
   };
 
   cmakeFlags = [
-    "-DTHREADSAFE=ON"
     "-DUSE_HTTP_PARSER=system"
     "-DUSE_SSH=ON"
     "-DBUILD_SHARED_LIBS=${if staticBuild then "OFF" else "ON"}"