diff --git a/modules/programs/firefox.nix b/modules/programs/firefox.nix
index 06c9aac7..a2eebdb4 100644
--- a/modules/programs/firefox.nix
+++ b/modules/programs/firefox.nix
@@ -600,7 +600,7 @@ in {
                           # like: [source]/path/to/engine.xml
                           loadPath = ''
                             [home-manager]/programs.firefox.profiles.${profile.name}.search.engines."${
-                              replaceChars [ "\\" ] [ "\\\\" ] name
+                              replaceStrings [ "\\" ] [ "\\\\" ] name
                             }"'';
                         })) // {
                           # Required fields for all engine configurations
diff --git a/modules/services/imapnotify.nix b/modules/services/imapnotify.nix
index 6a464ec8..0197ec54 100644
--- a/modules/services/imapnotify.nix
+++ b/modules/services/imapnotify.nix
@@ -6,7 +6,7 @@ let
 
   cfg = config.services.imapnotify;
 
-  safeName = lib.replaceChars [ "@" ":" "\\" "[" "]" ] [ "-" "-" "-" "" "" ];
+  safeName = lib.replaceStrings [ "@" ":" "\\" "[" "]" ] [ "-" "-" "-" "" "" ];
 
   imapnotifyAccounts =
     filter (a: a.imapnotify.enable) (attrValues config.accounts.email.accounts);
diff --git a/modules/systemd.nix b/modules/systemd.nix
index 6abc2460..e4c36ae4 100644
--- a/modules/systemd.nix
+++ b/modules/systemd.nix
@@ -8,7 +8,7 @@ let
 
   # From <nixpkgs/nixos/modules/system/boot/systemd-lib.nix>
   mkPathSafeName =
-    lib.replaceChars [ "@" ":" "\\" "[" "]" ] [ "-" "-" "-" "" "" ];
+    lib.replaceStrings [ "@" ":" "\\" "[" "]" ] [ "-" "-" "-" "" "" ];
 
   enabled = cfg.services != { } # \
     || cfg.slices != { } # \