diff --git a/pkgs/desktops/plasma-5.4/plasma-workspace/default.nix b/pkgs/desktops/plasma-5.4/plasma-workspace/default.nix
index 8fa5709feab..4a7f8b460ed 100644
--- a/pkgs/desktops/plasma-5.4/plasma-workspace/default.nix
+++ b/pkgs/desktops/plasma-5.4/plasma-workspace/default.nix
@@ -28,9 +28,6 @@ plasmaPackage rec {
     kidletime krunner ktexteditor kwin libkscreen libksysguard
     plasma-framework qtquick1 qtquickcontrols qtx11extras solid
   ];
-  # All propagatedBuildInputs should be present in the profile because
-  # impure wrappers are used below.
-  propagatedUserEnvPkgs = propagatedBuildInputs;
   patches = [ ./0001-startkde-NixOS-patches.patch ];
 
   inherit bash coreutils gnused gnugrep socat;
@@ -42,7 +39,6 @@ plasmaPackage rec {
       --replace kdostartupconfig5 $out/bin/kdostartupconfig5
   '';
   postInstall = ''
-    export QT_WRAPPER_IMPURE=1
     wrapQtProgram "$out/bin/ksmserver"
     wrapQtProgram "$out/bin/plasmawindowed"
     wrapQtProgram "$out/bin/kcminit_startup"
diff --git a/pkgs/development/libraries/qt-5/5.5/make-qt-wrapper.sh b/pkgs/development/libraries/qt-5/5.5/make-qt-wrapper.sh
index f4f13833b8d..156d794af7f 100644
--- a/pkgs/development/libraries/qt-5/5.5/make-qt-wrapper.sh
+++ b/pkgs/development/libraries/qt-5/5.5/make-qt-wrapper.sh
@@ -8,19 +8,11 @@ addQtDependency() {
 wrapQtProgram() {
     local prog="$1"
     shift
-    if [[ -n "$QT_WRAPPER_IMPURE" ]]; then
-        wrapProgram "$prog" \
-            --prefix QT_PLUGIN_PATH : "$QT_PLUGIN_PATH" \
-            --prefix QML_IMPORT_PATH : "$QML_IMPORT_PATH" \
-            --prefix QML2_IMPORT_PATH : "$QML2_IMPORT_PATH" \
-            "$@"
-    else
-        wrapProgram "$prog" \
-            --set QT_PLUGIN_PATH "$QT_PLUGIN_PATH" \
-            --set QML_IMPORT_PATH "$QML_IMPORT_PATH" \
-            --set QML2_IMPORT_PATH "$QML2_IMPORT_PATH" \
-            "$@"
-    fi
+    wrapProgram "$prog" \
+        --prefix QT_PLUGIN_PATH : "$QT_PLUGIN_PATH" \
+        --prefix QML_IMPORT_PATH : "$QML_IMPORT_PATH" \
+        --prefix QML2_IMPORT_PATH : "$QML2_IMPORT_PATH" \
+        "$@"
 }
 
 makeQtWrapper() {
@@ -28,19 +20,11 @@ makeQtWrapper() {
     local new="$2"
     shift
     shift
-    if [[ -n "$QT_WRAPPER_IMPURE" ]]; then
-        makeWrapper "$old" "$new" \
-            --prefix QT_PLUGIN_PATH : "$QT_PLUGIN_PATH" \
-            --prefix QML_IMPORT_PATH : "$QML_IMPORT_PATH" \
-            --prefix QML2_IMPORT_PATH : "$QML2_IMPORT_PATH" \
-            "$@"
-    else
-        makeWrapper "$old" "$new" \
-            --set QT_PLUGIN_PATH "$QT_PLUGIN_PATH" \
-            --set QML_IMPORT_PATH "$QML_IMPORT_PATH" \
-            --set QML2_IMPORT_PATH "$QML2_IMPORT_PATH" \
-            "$@"
-    fi
+    makeWrapper "$old" "$new" \
+        --prefix QT_PLUGIN_PATH : "$QT_PLUGIN_PATH" \
+        --prefix QML_IMPORT_PATH : "$QML_IMPORT_PATH" \
+        --prefix QML2_IMPORT_PATH : "$QML2_IMPORT_PATH" \
+        "$@"
 }
 
 # cannot use addToSearchPath because these directories may not exist yet