diff --git a/pkgs/data/icons/numix-icon-theme-circle/default.nix b/pkgs/data/icons/numix-icon-theme-circle/default.nix
index e46c7a4289b..7fe16f016cc 100644
--- a/pkgs/data/icons/numix-icon-theme-circle/default.nix
+++ b/pkgs/data/icons/numix-icon-theme-circle/default.nix
@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "numix-icon-theme-circle";
-  version = "20.09.19";
+  version = "21.04.14";
 
   src = fetchFromGitHub {
     owner = "numixproject";
     repo = pname;
     rev = version;
-    sha256 = "1rqlq5ssxqj0nc0i8av7zprj94km5645xzqi5j5i0sxd3jbmyfjx";
+    sha256 = "1z8c0179r8g0y9zh4383brsfhkcyfy79dc8hw94p9zjn5a66547w";
   };
 
   nativeBuildInputs = [ gtk3 ];
@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "Numix icon theme (circle version)";
     homepage = "https://numixproject.github.io";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     # darwin cannot deal with file names differing only in case
     platforms = platforms.linux;
     maintainers = with maintainers; [ romildo ];
diff --git a/pkgs/data/icons/numix-icon-theme-square/default.nix b/pkgs/data/icons/numix-icon-theme-square/default.nix
index bc243b95afc..9c7b1786a6e 100644
--- a/pkgs/data/icons/numix-icon-theme-square/default.nix
+++ b/pkgs/data/icons/numix-icon-theme-square/default.nix
@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "numix-icon-theme-square";
-  version = "20.09.19";
+  version = "21.04.14";
 
   src = fetchFromGitHub {
     owner = "numixproject";
     repo = pname;
     rev = version;
-    sha256 = "0afraarfcd66mpidmn0l90wif8kmwzdj3s09g704kwszyijxs80z";
+    sha256 = "0ndxjp173dwz78m41mn818mh4bdsxa2ypv4wrwicx0v4d8z90ddj";
   };
 
   nativeBuildInputs = [ gtk3 ];
@@ -37,7 +37,7 @@ stdenv.mkDerivation rec {
   meta = with lib; {
     description = "Numix icon theme (square version)";
     homepage = "https://numixproject.github.io";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     # darwin cannot deal with file names differing only in case
     platforms = platforms.linux;
     maintainers = with maintainers; [ romildo ];
diff --git a/pkgs/data/icons/numix-icon-theme/default.nix b/pkgs/data/icons/numix-icon-theme/default.nix
index d8e583b4bbb..194a36021a9 100644
--- a/pkgs/data/icons/numix-icon-theme/default.nix
+++ b/pkgs/data/icons/numix-icon-theme/default.nix
@@ -2,13 +2,13 @@
 
 stdenv.mkDerivation rec {
   pname = "numix-icon-theme";
-  version = "20.06.07";
+  version = "21.04.14";
 
   src = fetchFromGitHub {
     owner = "numixproject";
     repo = pname;
     rev = version;
-    sha256 = "1yp9parc8ihmai8pswf4qzrqd88qpls87ipq8ylx38yqns7wsn4h";
+    sha256 = "1ilzqh9f7skdfg5sl97zfgwrzvwa1zna22dpq0954gyyzvy7k7lg";
   };
 
   nativeBuildInputs = [ gtk3 ];
@@ -18,18 +18,22 @@ stdenv.mkDerivation rec {
   dontDropIconThemeCache = true;
 
   installPhase = ''
+    runHook preInstall
+
     mkdir -p $out/share/icons
     cp -a Numix{,-Light} $out/share/icons/
 
     for theme in $out/share/icons/*; do
       gtk-update-icon-cache $theme
     done
+
+    runHook postInstall
   '';
 
   meta = with lib; {
     description = "Numix icon theme";
     homepage = "https://numixproject.github.io";
-    license = licenses.gpl3;
+    license = licenses.gpl3Only;
     # darwin cannot deal with file names differing only in case
     platforms = platforms.linux;
     maintainers = with maintainers; [ romildo ];