diff --git a/nixos/modules/services/web-apps/grocy.nix b/nixos/modules/services/web-apps/grocy.nix
index 3bcda3caedaced..688367cafaf55f 100644
--- a/nixos/modules/services/web-apps/grocy.nix
+++ b/nixos/modules/services/web-apps/grocy.nix
@@ -117,7 +117,9 @@ in {
 
       # PHP 8.0 is the only version which is supported/tested by upstream:
       # https://github.com/grocy/grocy/blob/v3.3.0/README.md#how-to-install
-      phpPackage = pkgs.php80;
+      # Compatibility with PHP 8.1 is available on their development branch:
+      # https://github.com/grocy/grocy/commit/38a4ad8ec480c29a1bff057b3482fd103b036848
+      phpPackage = pkgs.php81;
 
       inherit (cfg.phpfpm) settings;
 
diff --git a/nixos/modules/services/web-apps/limesurvey.nix b/nixos/modules/services/web-apps/limesurvey.nix
index 8e6b39cbdebcb4..920e6928ef5ceb 100644
--- a/nixos/modules/services/web-apps/limesurvey.nix
+++ b/nixos/modules/services/web-apps/limesurvey.nix
@@ -226,7 +226,7 @@ in
 
     services.phpfpm.pools.limesurvey = {
       inherit user group;
-      phpPackage = pkgs.php80;
+      phpPackage = pkgs.php81;
       phpEnv.DBENGINE = "${cfg.database.dbEngine}";
       phpEnv.LIMESURVEY_CONFIG = "${limesurveyConfig}";
       settings = {
@@ -288,8 +288,8 @@ in
       environment.LIMESURVEY_CONFIG = limesurveyConfig;
       script = ''
         # update or install the database as required
-        ${pkgs.php80}/bin/php ${pkg}/share/limesurvey/application/commands/console.php updatedb || \
-        ${pkgs.php80}/bin/php ${pkg}/share/limesurvey/application/commands/console.php install admin password admin admin@example.com verbose
+        ${pkgs.php81}/bin/php ${pkg}/share/limesurvey/application/commands/console.php updatedb || \
+        ${pkgs.php81}/bin/php ${pkg}/share/limesurvey/application/commands/console.php install admin password admin admin@example.com verbose
       '';
       serviceConfig = {
         User = user;
diff --git a/pkgs/servers/grocy/default.nix b/pkgs/servers/grocy/default.nix
index 360f5202e28a26..bbae0f8f248fd3 100644
--- a/pkgs/servers/grocy/default.nix
+++ b/pkgs/servers/grocy/default.nix
@@ -36,5 +36,6 @@ stdenv.mkDerivation rec {
     maintainers = with maintainers; [ ma27 ];
     description = "ERP beyond your fridge - grocy is a web-based self-hosted groceries & household management solution for your home";
     homepage = "https://grocy.info/";
+    broken = true; # Not compatible with PHP 8.1
   };
 }
diff --git a/pkgs/servers/limesurvey/default.nix b/pkgs/servers/limesurvey/default.nix
index ce75e8de8b5a32..b9eb173bb7d393 100644
--- a/pkgs/servers/limesurvey/default.nix
+++ b/pkgs/servers/limesurvey/default.nix
@@ -37,5 +37,6 @@ stdenv.mkDerivation rec {
     homepage = "https://www.limesurvey.org";
     maintainers = with maintainers; [offline];
     platforms = with platforms; unix;
+    broken = true; # Not compatible with PHP 8.1
   };
 }