diff --git a/nix/packages/by-name/ai_blocklist/package.nix b/nix/packages/by-name/ai_blocklist/package.nix
index ecfd0db0..c967b129 100644
--- a/nix/packages/by-name/ai_blocklist/package.nix
+++ b/nix/packages/by-name/ai_blocklist/package.nix
@@ -17,6 +17,10 @@ stdenvNoCC.mkDerivation {
     hash = "sha256-p3wfR28DH6V8BHn9DT10d09Yq3mdbBecWwlR1CdDYUA=";
   };
 
+  # Build takes no time
+  preferLocalBuild = true;
+  allowSubstitutes = false;
+
   installPhase = ''
     mkdir -p $out/share
     cp noai_hosts.txt $out/share/hosts.txt
diff --git a/nix/packages/by-name/hategroup_blocklist/package.nix b/nix/packages/by-name/hategroup_blocklist/package.nix
index d7fb0e86..3dc813bb 100644
--- a/nix/packages/by-name/hategroup_blocklist/package.nix
+++ b/nix/packages/by-name/hategroup_blocklist/package.nix
@@ -17,6 +17,10 @@ stdenvNoCC.mkDerivation {
     hash = "sha256-SZBrjIBUw687MdrbOV7WrP5IhAAtKvPL2GqdcICHNvQ=";
   };
 
+  # Build takes no time
+  preferLocalBuild = true;
+  allowSubstitutes = false;
+
   installPhase = ''
     mkdir -p $out/share
     cp blocklist.txt $out/share/domains.txt
diff --git a/nix/packages/by-name/hrt-time/package.nix b/nix/packages/by-name/hrt-time/package.nix
index 713bb8f1..29a50de3 100644
--- a/nix/packages/by-name/hrt-time/package.nix
+++ b/nix/packages/by-name/hrt-time/package.nix
@@ -17,6 +17,10 @@ stdenvNoCC.mkDerivation {
     hash = "sha256-+AhLkcCETVnF6S+ov1oKxhs3M9F6ghyyERoLN3aMMxw=";
   };
 
+  # Build takes no time
+  preferLocalBuild = true;
+  allowSubstitutes = false;
+
   installPhase = ''
     mkdir -p $out/bin
     cp hrt-time.sh $out/bin/hrt-time