diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 79a134c2d36b..127bf01abd47 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -10158,7 +10158,13 @@ in
   python2Packages = python2.pkgs;
   python3Packages = python3.pkgs;
 
-  pythonInterpreters = callPackage ./../development/interpreters/python {};
+  pythonInterpreters = callPackage ./../development/interpreters/python {
+    # Overrides that apply to all Python interpreters
+    pkgs = pkgs // {
+      qt5 = pkgs.qt514;
+      libsForQt5 = pkgs.libsForQt514;
+    };
+  };
   inherit (pythonInterpreters) python27 python36 python37 python38 python39 python3Minimal pypy27 pypy36;
 
   # Python package sets.
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 312527a39b59..b0bf49fe1033 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -14,11 +14,6 @@
 
 with pkgs.lib;
 
-let
-  qt5 = pkgs.qt514;
-  libsForQt5 = pkgs.libsForQt514;
-in
-
 let
   packages = ( self:
 
@@ -3598,7 +3593,7 @@ in {
 
   maya = callPackage ../development/python-modules/maya { };
 
-  mayavi = libsForQt5.callPackage ../development/python-modules/mayavi {
+  mayavi = pkgs.libsForQt5.callPackage ../development/python-modules/mayavi {
     inherit buildPythonPackage isPy27 fetchPypi;
     inherit (self) pyface pygments numpy vtk traitsui envisage apptools pyqt5;
   };
@@ -4188,7 +4183,7 @@ in {
 
   ovh = callPackage ../development/python-modules/ovh { };
 
-  ovito = toPythonModule (libsForQt5.callPackage ../development/python-modules/ovito { pythonPackages = self; });
+  ovito = toPythonModule (pkgs.libsForQt5.callPackage ../development/python-modules/ovito { pythonPackages = self; });
 
   owslib = callPackage ../development/python-modules/owslib { };
 
@@ -4440,8 +4435,8 @@ in {
   pipx = callPackage ../development/python-modules/pipx { };
 
   pivy = callPackage ../development/python-modules/pivy {
-    inherit (qt5) qtbase qmake;
-    inherit (libsForQt5) soqt;
+    inherit (pkgs.qt5) qtbase qmake;
+    inherit (pkgs.libsForQt5) soqt;
   };
 
   pkgconfig = callPackage ../development/python-modules/pkgconfig { inherit (pkgs) pkgconfig; };
@@ -4513,8 +4508,8 @@ in {
   pooch = callPackage ../development/python-modules/pooch { };
 
   poppler-qt5 = callPackage ../development/python-modules/poppler-qt5 {
-    inherit (qt5) qtbase;
-    inherit (libsForQt5) poppler;
+    inherit (pkgs.qt5) qtbase;
+    inherit (pkgs.libsForQt5) poppler;
     inherit (pkgs) pkgconfig;
   };
 
@@ -5219,7 +5214,7 @@ in {
 
   pyqt4 = callPackage ../development/python-modules/pyqt/4.x.nix { inherit (pkgs) pkgconfig; };
 
-  pyqt5 = libsForQt5.callPackage ../development/python-modules/pyqt/5.x.nix { pythonPackages = self; };
+  pyqt5 = pkgs.libsForQt5.callPackage ../development/python-modules/pyqt/5.x.nix { pythonPackages = self; };
 
   pyqt5_with_qtmultimedia = self.pyqt5.override { withMultimedia = true; };
 
@@ -5232,7 +5227,7 @@ in {
 
   pyqtgraph = callPackage ../development/python-modules/pyqtgraph { };
 
-  pyqtwebengine = libsForQt5.callPackage ../development/python-modules/pyqtwebengine { pythonPackages = self; };
+  pyqtwebengine = pkgs.libsForQt5.callPackage ../development/python-modules/pyqtwebengine { pythonPackages = self; };
 
   pyquery = callPackage ../development/python-modules/pyquery { };
 
@@ -5338,9 +5333,9 @@ in {
   pyshp = callPackage ../development/python-modules/pyshp { };
 
   pyside2-tools =
-    toPythonModule (callPackage ../development/python-modules/pyside2-tools { inherit (pkgs) cmake; inherit qt5; });
+    toPythonModule (callPackage ../development/python-modules/pyside2-tools { inherit (pkgs) cmake qt5; });
 
-  pyside2 = toPythonModule (callPackage ../development/python-modules/pyside2 { inherit (pkgs) cmake ninja; inherit qt5; });
+  pyside2 = toPythonModule (callPackage ../development/python-modules/pyside2 { inherit (pkgs) cmake ninja qt5; });
 
   pyside = callPackage ../development/python-modules/pyside { inherit (pkgs) mesa; };
 
@@ -5941,7 +5936,7 @@ in {
 
   qscintilla-qt4 = callPackage ../development/python-modules/qscintilla { };
 
-  qscintilla-qt5 = libsForQt5.callPackage ../development/python-modules/qscintilla-qt5 { pythonPackages = self; };
+  qscintilla-qt5 = pkgs.libsForQt5.callPackage ../development/python-modules/qscintilla-qt5 { pythonPackages = self; };
 
   qscintilla = self.qscintilla-qt4;
 
@@ -6122,7 +6117,7 @@ in {
 
   roboschool = callPackage ../development/python-modules/roboschool {
     inherit (pkgs) pkgconfig; # use normal pkgconfig, not the python package
-    inherit (qt5) qtbase;
+    inherit (pkgs.qt5) qtbase;
   };
 
   robot-detection = callPackage ../development/python-modules/robot-detection { };
@@ -6408,7 +6403,7 @@ in {
   shellingham = callPackage ../development/python-modules/shellingham { };
 
   shiboken2 =
-    toPythonModule (callPackage ../development/python-modules/shiboken2 { inherit (pkgs) cmake llvmPackages; inherit qt5; });
+    toPythonModule (callPackage ../development/python-modules/shiboken2 { inherit (pkgs) cmake llvmPackages qt5; });
 
   shippai = callPackage ../development/python-modules/shippai { };