diff --git a/pkgs/applications/networking/instant-messengers/linphone/mediastreamer2/default.nix b/pkgs/applications/networking/instant-messengers/linphone/mediastreamer2/default.nix
index 0ed276b28b89..f4f3561ecd3e 100644
--- a/pkgs/applications/networking/instant-messengers/linphone/mediastreamer2/default.nix
+++ b/pkgs/applications/networking/instant-messengers/linphone/mediastreamer2/default.nix
@@ -70,7 +70,7 @@ mkLinphoneDerivation (finalAttrs: {
     "-DENABLE_UNIT_TESTS=NO" # Do not build test executables
   ];
 
-  NIX_LDFLAGS = "-lXext";
+  env.NIX_LDFLAGS = "-lXext";
 
   meta = {
     description = "Powerful and lightweight streaming engine specialized for voice/video telephony applications. Part of the Linphone project";