diff --git a/src/libvterm/include/vterm.h b/src/libvterm/include/vterm.h
index 5bc47e5..ccd10c5 100644
--- a/src/libvterm/include/vterm.h
+++ b/src/libvterm/include/vterm.h
@@ -10,10 +10,12 @@
 
 #include <stdint.h>
 #include <stdlib.h>
-#include <stdbool.h>
 
 #include "vterm_keycodes.h"
 
+#define TRUE 1
+#define FALSE 0
+
 typedef struct VTerm VTerm;
 typedef struct VTermState VTermState;
 typedef struct VTermScreen VTermScreen;
@@ -183,7 +185,7 @@
 void vterm_keyboard_end_paste(VTerm *vt);
 
 void vterm_mouse_move(VTerm *vt, int row, int col, VTermModifier mod);
-void vterm_mouse_button(VTerm *vt, int button, bool pressed, VTermModifier mod);
+void vterm_mouse_button(VTerm *vt, int button, int pressed, VTermModifier mod);
 
 /* ------------
  * Parser layer
@@ -235,6 +237,8 @@
   int (*erase)(VTermRect rect, int selective, void *user);
   int (*initpen)(void *user);
   int (*setpenattr)(VTermAttr attr, VTermValue *val, void *user);
+  /* Callback for setting various properties.  Must return 1 if the property
+   * was accepted, 0 otherwise. */
   int (*settermprop)(VTermProp prop, VTermValue *val, void *user);
   int (*bell)(void *user);
   int (*resize)(int rows, int cols, VTermPos *delta, void *user);