diff --git a/contrib/bkgrnd2d/plugin.cpp b/contrib/bkgrnd2d/plugin.cpp
index 09e9ed7c..a37882c5 100644
--- a/contrib/bkgrnd2d/plugin.cpp
+++ b/contrib/bkgrnd2d/plugin.cpp
@@ -97,9 +97,9 @@ void DoBkgrndToggleYZ();
 #define NUM_TOOLBAR_BUTTONS 4
 struct toolbar_button_info_s
 {
-	char *image;
-	char *text;
-	char *tip;
+	const char *image;
+	const char *text;
+	const char *tip;
 	void (*func)();
 	IToolbarButton::EType type;
 };