diff --git a/lib/isc/include/isc/print.h b/lib/isc/include/isc/print.h
index 277829fd0c..d7fca7442d 100644
--- a/lib/isc/include/isc/print.h
+++ b/lib/isc/include/isc/print.h
@@ -77,29 +77,34 @@ ISC_LANG_BEGINDECLS
 int
 isc_print_vsnprintf(char *str, size_t size, const char *format, va_list ap)
      ISC_FORMAT_PRINTF(3, 0);
+#undef vsnprintf
 #define vsnprintf isc_print_vsnprintf
 
 int
 isc_print_snprintf(char *str, size_t size, const char *format, ...)
      ISC_FORMAT_PRINTF(3, 4);
+#undef snprintf
 #define snprintf isc_print_snprintf
 #endif /* ISC_PLATFORM_NEEDVSNPRINTF */
 
 #ifdef ISC_PLATFORM_NEEDSPRINTF
 int
 isc_print_sprintf(char *str, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);
+#undef sprintf
 #define sprintf isc_print_sprintf
 #endif
 
 #ifdef ISC_PLATFORM_NEEDPRINTF
 int
 isc_print_printf(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);
+#undef printf
 #define printf isc_print_printf
 #endif
 
 #ifdef ISC_PLATFORM_NEEDFPRINTF
 int
 isc_print_fprintf(FILE * fp, const char *format, ...) ISC_FORMAT_PRINTF(2, 3);
+#undef fprintf
 #define fprintf isc_print_fprintf
 #endif