diff --git a/gptel-contexter.el b/gptel-contexter.el
index 558bd21..154dade 100644
--- a/gptel-contexter.el
+++ b/gptel-contexter.el
@@ -47,6 +47,11 @@
                         'gptel-remove-context-at-point-from-context-buffer)
             map))
 
+(defcustom gptel-contexter-selection-face 'secondary-selection
+  "Face to use to highlight selected context in the buffers."
+  :group 'gptel
+  :type 'symbol)
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;; ------------------------------ FUNCTIONS ------------------------------- ;;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -54,7 +59,7 @@
 (defun gptel--highlight-region (start end)
   "Highlight the region from START to END."
   (let ((overlay (make-overlay start end)))
-    (overlay-put overlay 'face 'secondary-selection)
+    (overlay-put overlay 'face gptel-contexter-selection-face)
     (overlay-put overlay 'contexter t)))
 
 (defun gptel--unhighlight-region (start end)