diff --git a/data/scripts/o b/data/scripts/o
index c0e318c..17ef3c3 100755
--- a/data/scripts/o
+++ b/data/scripts/o
@@ -392,10 +392,12 @@ cmd_tui() {
 
     local s="$CTX_SESSION"
     local a="$CTX_AGENT"
-    # Sanitize session name for tmux (replace / and : with -)
+    # Sanitize session and agent names for tmux (replace / and : with -)
     local safe_session="${s//\//-}"
     safe_session="${safe_session//:/-}"
-    local tmux_session="o-${safe_session}-${a}"
+    local safe_agent="${a//\//-}"
+    safe_agent="${safe_agent//:/-}"
+    local tmux_session="o-${safe_session}-${safe_agent}"
 
     # Check for subcommands
     if [[ "${1:-}" == "exit" ]]; then