diff --git a/tmux.conf b/tmux.conf
index 94dca32..b6b9431 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -20,6 +20,12 @@ unbind C-b
 # ─< set the prefix to "C-Space" >────────────────────────────────────────────────────────
 set -g prefix C-Space
 bind C-Space send-prefix
+
+# ─< set the prefix2 to "C-b" >────────────────────────────────────────────────────────
+# NOTE: for guacamole use
+set -g prefix2 C-b
+bind C-b send-prefix
+
 bind h copy-mode
 
 set -g visual-activity on