diff --git a/libpcp/mgmt.c b/libpcp/mgmt.c
index 810e69f..5d37f70 100644
--- a/libpcp/mgmt.c
+++ b/libpcp/mgmt.c
@@ -19,8 +19,7 @@
     You can contact me by mail: <tom AT vondein DOT org>.
 */
 
-#define _XOPEN_SOURCE /* strptime, linux glibc*/
-#define _BSD_SOURCE
+/* #define _XOPEN_SOURCE strptime, linux glibc*/ 
 
 #include "mgmt.h"
 
diff --git a/src/pcp.h b/src/pcp.h
index fb44e43..5344671 100644
--- a/src/pcp.h
+++ b/src/pcp.h
@@ -23,8 +23,10 @@
 #ifndef _HAVE_PCP_H
 #define _HAVE_PCP_H
 
-#ifndef _BSD_SOURCE
-#define _BSD_SOURCE
+#if defined __linux__ || defined __GNU__ || defined __GLIBC__
+#define _DEFAULT_SOURCE 1
+#else
+#define _BSD_SOURCE 1
 #endif
 
 #include <unistd.h>
diff --git a/src/z85util.h b/src/z85util.h
index 40eaeb2..7aa6435 100644
--- a/src/z85util.h
+++ b/src/z85util.h
@@ -23,10 +23,6 @@
 #ifndef _HAVE_PCP_Z85
 #define _HAVE_PCP_Z85
 
-#ifndef _BSD_SOURCE
-#define _BSD_SOURCE
-#endif
-
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>