diff --git a/pkgs/ref-irc/default.nix b/pkgs/ref-irc/default.nix
index 89008a0..e2e7fd0 100644
--- a/pkgs/ref-irc/default.nix
+++ b/pkgs/ref-irc/default.nix
@@ -5,7 +5,7 @@
 writeShellApplication {
   name = "ref-irc";
 
-  runtimeInputs = [pkgs.tmux pkgs.gnugrep pkgs.weechat-unwrapped];
+  runtimeInputs = [pkgs.tmux pkgs.weechat-unwrapped];
 
   text = builtins.readFile ./script.sh;
 }
diff --git a/pkgs/ref-irc/script.sh b/pkgs/ref-irc/script.sh
index 11d5870..edeebbd 100644
--- a/pkgs/ref-irc/script.sh
+++ b/pkgs/ref-irc/script.sh
@@ -4,8 +4,8 @@ SESSION_NAME="irc"
 SESSION_DIR="$HOME"
 SESSION_CMD="weechat"
 
-if ! tmux list-session | grep -q "$SESSION_NAME"; then
-  tmux new-session -d -s "$SESSION_NAME" -c "$SESSION_DIR" "$SESSION_CMD"
+if ! tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+    tmux new-session -d -s "$SESSION_NAME" -c "$SESSION_DIR" "$SESSION_CMD"
 fi
 
 tmux switch-client -t "$SESSION_NAME"
diff --git a/pkgs/ref-mail/default.nix b/pkgs/ref-mail/default.nix
index 11866da..80533c7 100644
--- a/pkgs/ref-mail/default.nix
+++ b/pkgs/ref-mail/default.nix
@@ -5,7 +5,7 @@
 writeShellApplication {
   name = "ref-mail";
 
-  runtimeInputs = [pkgs.tmux pkgs.gnugrep pkgs.neomutt pkgs.lynx];
+  runtimeInputs = [pkgs.tmux pkgs.neomutt pkgs.lynx];
 
   text = builtins.readFile ./script.sh;
 }
diff --git a/pkgs/ref-mail/script.sh b/pkgs/ref-mail/script.sh
index 9db67ac..47b99c9 100644
--- a/pkgs/ref-mail/script.sh
+++ b/pkgs/ref-mail/script.sh
@@ -4,7 +4,7 @@ SESSION_NAME="mail"
 SESSION_DIR="$HOME/.Mail/private"
 SESSION_CMD="neomutt"
 
-if ! tmux list-session | grep -q "$SESSION_NAME"; then
+if ! tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
   tmux new-session -d -s "$SESSION_NAME" -c "$SESSION_DIR" "$SESSION_CMD"
 fi
 
diff --git a/pkgs/ref-main/default.nix b/pkgs/ref-main/default.nix
index e4bc3c9..35f9d4a 100644
--- a/pkgs/ref-main/default.nix
+++ b/pkgs/ref-main/default.nix
@@ -11,7 +11,7 @@
 writeShellApplication {
   name = "ref-main";
 
-  runtimeInputs = [pkgs.tmux pkgs.gnugrep];
+  runtimeInputs = [pkgs.tmux];
 
   # excludeShellChecks = [ "SC2148" ];
   text = builtins.readFile ./script.sh;
diff --git a/pkgs/ref-main/script.sh b/pkgs/ref-main/script.sh
index 4b60cba..8e709c4 100644
--- a/pkgs/ref-main/script.sh
+++ b/pkgs/ref-main/script.sh
@@ -3,13 +3,13 @@
 SESSION_NAME="main"
 SESSION_DIR="$HOME"
 
-if ! tmux server-info > /dev/null 2>&1; then
-  tmux new-session -s "$SESSION_NAME" -c "$SESSION_DIR"
-  exit 0
+if ! tmux server-info >/dev/null 2>&1; then
+    tmux new-session -s "$SESSION_NAME" -c "$SESSION_DIR"
+    exit 0
 fi
 
-if ! tmux list-session | grep -q "$SESSION_NAME"; then
-  tmux new-session -d -s "$SESSION_NAME" -c "$SESSION_DIR"
+if ! tmux has-session -t "$SESSION_NAME" 2>/dev/null; then
+    tmux new-session -d -s "$SESSION_NAME" -c "$SESSION_DIR"
 fi
 
 tmux switch-client -t "$SESSION_NAME"