diff --git a/contrib/ivorysql_ora/src/xml_functions/ora_xml_functions.c b/contrib/ivorysql_ora/src/xml_functions/ora_xml_functions.c
index 3c1549d0f64..23e8ac4f51b 100644
--- a/contrib/ivorysql_ora/src/xml_functions/ora_xml_functions.c
+++ b/contrib/ivorysql_ora/src/xml_functions/ora_xml_functions.c
@@ -2466,6 +2466,6 @@ Datum ivy_xmlisvalid(PG_FUNCTION_ARGS)
 	}
 #else
 	NO_XML_SUPPORT();
-	return NULL;
+	return 0;
 #endif
 }
diff --git a/src/interfaces/libpq/libpq-fe.h b/src/interfaces/libpq/libpq-fe.h
index 24f60f14acb..4880302b659 100644
--- a/src/interfaces/libpq/libpq-fe.h
+++ b/src/interfaces/libpq/libpq-fe.h
@@ -20,6 +20,7 @@ extern "C"
 {
 #endif
 
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 
@@ -71,14 +72,6 @@ extern "C"
 #define PG_COPYRES_EVENTS		  0x04
 #define PG_COPYRES_NOTICEHOOKS	  0x08
 
-/*
- * Assume bool has been defined if true and false are defined.  
- * This avoids duplicate-typedef errors if this file is included after c.h.
- */
-#if !(defined(true) && defined(false))
-typedef unsigned char bool;
-#endif
-
 /* Application-visible enum types */
 
 /*