diff --git a/modules/programs/tmux.nix b/modules/programs/tmux.nix
index ed9876ea1..df3ed11d5 100644
--- a/modules/programs/tmux.nix
+++ b/modules/programs/tmux.nix
@@ -336,7 +336,7 @@ in {
 
     (mkIf cfg.secureSocket {
       home.sessionVariables = {
-        TMUX_TMPDIR = ''''${XDG_RUNTIME_DIR:-"/run/user/\$(id -u)"}'';
+        TMUX_TMPDIR = ''''${XDG_RUNTIME_DIR:-"/run/user/$(id -u)"}'';
       };
     })
 
diff --git a/tests/modules/programs/tmux/secure-socket-enabled.nix b/tests/modules/programs/tmux/secure-socket-enabled.nix
index ca2de6631..60b3f7087 100644
--- a/tests/modules/programs/tmux/secure-socket-enabled.nix
+++ b/tests/modules/programs/tmux/secure-socket-enabled.nix
@@ -12,7 +12,7 @@ with lib;
     nmt.script = ''
       assertFileExists home-path/etc/profile.d/hm-session-vars.sh
       assertFileContains home-path/etc/profile.d/hm-session-vars.sh \
-        'export TMUX_TMPDIR="''${XDG_RUNTIME_DIR:-"/run/user/\$(id -u)"}"'
+        'export TMUX_TMPDIR="''${XDG_RUNTIME_DIR:-"/run/user/$(id -u)"}"'
     '';
   };
 }