diff --git a/mapproject.h b/mapproject.h
index c296677..4695e90 100644
--- a/mapproject.h
+++ b/mapproject.h
@@ -38,6 +38,7 @@ extern "C" {
 #endif
 
 #ifdef USE_PROJ
+#define ACCEPT_USE_OF_DEPRECATED_PROJ_API_H
 #  include <proj_api.h>
 #if PJ_VERSION >= 470 && PJ_VERSION < 480
    void pj_clear_initcache();