diff --git a/textscreen/txt_radiobutton.c b/textscreen/txt_radiobutton.c
index 31d9fb9d..1319bd69 100644
--- a/textscreen/txt_radiobutton.c
+++ b/textscreen/txt_radiobutton.c
@@ -121,7 +121,7 @@ txt_widget_class_t txt_radiobutton_class =
     NULL,
 };
 
-txt_radiobutton_t *TXT_NewRadioButton(char *label, int *variable, int value)
+txt_radiobutton_t *TXT_NewRadioButton(const char *label, int *variable, int value)
 {
     txt_radiobutton_t *radiobutton;
 
diff --git a/textscreen/txt_radiobutton.h b/textscreen/txt_radiobutton.h
index 9e550733..6ba25a5f 100644
--- a/textscreen/txt_radiobutton.h
+++ b/textscreen/txt_radiobutton.h
@@ -63,7 +63,7 @@ struct txt_radiobutton_s
  * @return               Pointer to the new radio button widget.
  */
 
-txt_radiobutton_t *TXT_NewRadioButton(char *label, int *variable, int value);
+txt_radiobutton_t *TXT_NewRadioButton(const char *label, int *variable, int value);
 
 /**
  * Set the label on a radio button.