diff --git a/test/ssltest.c b/test/ssltest.c
index 1128ec83b850e9dc2d126c109e4a843bff2d0267..68d48d1d739b6c4f649689eb0ff03c271b653df7 100644
--- a/test/ssltest.c
+++ b/test/ssltest.c
@@ -142,6 +142,7 @@
 
 /* Or gethostname won't be declared properly on Linux and GNU platforms. */
 #define _BSD_SOURCE 1
+#define _DEFAULT_SOURCE 1
 
 #include <assert.h>
 #include <errno.h>