diff --git a/runtime/include/sys_basic.h b/runtime/include/sys_basic.h
index 23e5ebb..da9cef9 100644
--- a/runtime/include/sys_basic.h
+++ b/runtime/include/sys_basic.h
@@ -52,6 +52,12 @@
 #define _POSIX_C_SOURCE 200112L
 #endif
 
+#ifndef _DEFAULT_SOURCE
+// Quiets warnings about _BSD_SOURCE being deprecated in glbic >= 2.20
+// This define enables everything _BSD_SOURCE does (and more) with glibc >= 2.19
+#define _DEFAULT_SOURCE
+#endif
+
 //
 // The following breaks #include of "glob.h" with the Cray CCE
 // compiler and also complicates things for the #inclusion of dirent.h