2 files changed, 0 insertions, 4 deletions
diff --git a/pkgs/development/libraries/msgpack/generic.nix b/pkgs/development/libraries/msgpack/generic.nix
index 306becf0c180..de277329961b 100644
--- a/pkgs/development/libraries/msgpack/generic.nix
+++ b/pkgs/development/libraries/msgpack/generic.nix
@@ -15,8 +15,6 @@ stdenv.mkDerivation rec {
   cmakeFlags = []
     ++ stdenv.lib.optional (stdenv.hostPlatform != stdenv.buildPlatform)
                            "-DMSGPACK_BUILD_EXAMPLES=OFF"
-    ++ stdenv.lib.optional (stdenv.hostPlatform.libc == "msvcrt")
-                           "-DCMAKE_SYSTEM_NAME=Windows"
     ;
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/libraries/nlohmann_json/default.nix b/pkgs/development/libraries/nlohmann_json/default.nix
index ffb735e725ae..25d4386cec2c 100644
--- a/pkgs/development/libraries/nlohmann_json/default.nix
+++ b/pkgs/development/libraries/nlohmann_json/default.nix
@@ -18,8 +18,6 @@ stdenv.mkDerivation rec {
 
   cmakeFlags = [
     "-DBuildTests=${if doCheck then "ON" else "OFF"}"
-  ] ++ stdenv.lib.optionals (stdenv.hostPlatform.libc == "msvcrt") [
-    "-DCMAKE_SYSTEM_NAME=Windows"
   ];
 
   doCheck = stdenv.hostPlatform == stdenv.buildPlatform;