diff --git a/pkgs/desktops/plasma-5.2/default.nix b/pkgs/desktops/plasma-5.2/default.nix
index 28bdc26bd4e6..4646fda268d9 100644
--- a/pkgs/desktops/plasma-5.2/default.nix
+++ b/pkgs/desktops/plasma-5.2/default.nix
@@ -127,10 +127,6 @@ let
           substituteInPlace kcms/dateandtime/helper.cpp \
             --subst-var-by hwclock "${utillinux}/sbin/hwclock"
         '';
-        enableParallelBuilding = false;
-        NIX_CFLAGS_COMPILE =
-          (super.plasma-desktop.NIX_CFLAGS_COMPILE or "")
-          + " -Wno-error=return-type";
       };
 
       plasma-workspace = with pkgs; super.plasma-workspace // {
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 302033144861..de8804484819 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -5814,9 +5814,7 @@ let
   kf55 = recurseIntoAttrs (callPackage ../development/libraries/kde-frameworks-5.5 {
     stdenv = overrideGCC stdenv gccStdInc;
   });
-  kf56 = recurseIntoAttrs (callPackage ../development/libraries/kde-frameworks-5.6 {
-    stdenv = overrideGCC stdenv gccStdInc;
-  });
+  kf56 = recurseIntoAttrs (callPackage ../development/libraries/kde-frameworks-5.6 {});
   kf5_latest = kf56;
   kf5_stable = kf55;
 
@@ -12462,9 +12460,7 @@ let
   plasma51 = recurseIntoAttrs (callPackage ../desktops/plasma-5.1 {
     stdenv = overrideGCC stdenv gccStdInc;
   });
-  plasma52 = recurseIntoAttrs (callPackage ../desktops/plasma-5.2 {
-    stdenv = overrideGCC stdenv gccStdInc;
-  });
+  plasma52 = recurseIntoAttrs (callPackage ../desktops/plasma-5.2 {});
   plasma5_latest = plasma52;
   plasma5_stable = plasma51;