diff --git a/poppler/Object.h b/poppler/Object.h
--- a/poppler/Object.h
+++ b/poppler/Object.h
@@ -46,14 +46,14 @@
 
 #define OBJECT_TYPE_CHECK(wanted_type) \
     if (unlikely(type != wanted_type)) { \
-        error(0, "Call to Object where the object was type %d, " \
+        error(0, (char*) "Call to Object where the object was type %d, " \
                  "not the expected type %d", type, wanted_type); \
         abort(); \
     }
 
 #define OBJECT_2TYPES_CHECK(wanted_type1, wanted_type2) \
     if (unlikely(type != wanted_type1) && unlikely(type != wanted_type2)) { \
-        error(0, "Call to Object where the object was type %d, " \
+        error(0, (char*) "Call to Object where the object was type %d, " \
                  "not the expected type %d or %d", type, wanted_type1, wanted_type2); \
         abort(); \
     }