diff --git a/modules/mu/default.nix b/modules/mu/default.nix
index 8490c842d..8b37d9c5b 100644
--- a/modules/mu/default.nix
+++ b/modules/mu/default.nix
@@ -11,6 +11,7 @@ in
 {
   imports = [
     <secrets/mu.hashedPasswords.nix>
+    ../common/nixpkgs.nix
     ../tv/base.nix
     ../tv/exim-retiolum.nix
     ../tv/retiolum.nix
@@ -19,6 +20,11 @@ in
 
   nix.maxJobs = 2;
 
+  nixpkgs = {
+    url = "https://github.com/NixOS/nixpkgs";
+    rev = "4c01e6d91993b6de128795f4fbdd25f6227fb870";
+  };
+
   services.udev.extraRules = ''
     SUBSYSTEM=="net", ATTR{address}=="00:90:f5:da:aa:c3", NAME="en0"
     SUBSYSTEM=="net", ATTR{address}=="a0:88:b4:1b:ae:6c", NAME="wl0"
diff --git a/modules/wu/default.nix b/modules/wu/default.nix
index fbbeba2b6..3258779ee 100644
--- a/modules/wu/default.nix
+++ b/modules/wu/default.nix
@@ -10,6 +10,7 @@ in
   imports = [
     ./hosts.nix
     ./iptables.nix
+    ../common/nixpkgs.nix
     ../tv/base.nix
     ../tv/exim-retiolum.nix
     ../tv/nginx.nix
@@ -25,6 +26,10 @@ in
 
   nix.maxJobs = 8;
 
+  nixpkgs = {
+    url = "https://github.com/NixOS/nixpkgs";
+    rev = "4c01e6d91993b6de128795f4fbdd25f6227fb870";
+  };
 
   services.udev.extraRules = ''
     SUBSYSTEM=="net", ATTR{address}=="00:90:f5:da:aa:c3", NAME="en0"