diff --git a/src/core/resolve.c b/src/core/resolve.c
index de5a30398e0..6edc47e5068 100644
--- a/src/core/resolve.c
+++ b/src/core/resolve.c
@@ -32,6 +32,13 @@
 #include <resolv.h>
 #include <string.h>
 
+/* older glibc < 2.25 does not include T_OPT in nameser_compat.h yet */
+#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 25
+#ifndef T_OPT
+#define T_OPT ns_t_opt
+#endif
+#endif
+
 #include "resolve.h"
 #include "compiler_opt.h"
 #include "dprint.h"