diff --git a/libmudflap/ChangeLog b/libmudflap/ChangeLog
index 72359100dee..dcd649fe6bb 100644
--- a/libmudflap/ChangeLog
+++ b/libmudflap/ChangeLog
@@ -1,3 +1,7 @@
+2004-08-03  Dale Johannesen  <dalej@apple.com>
+
+         * mf-runtime.c: Conditionalize POSIX_SOURCE for Darwin.
+
 2004-08-03  Frank Ch. Eigler  <fche@redhat.com>
 
 	* mf-runtime.c (compare_uintptr_t): Remove function.  Inline
diff --git a/libmudflap/mf-runtime.c b/libmudflap/mf-runtime.c
index d8ba77531cf..f374577191a 100644
--- a/libmudflap/mf-runtime.c
+++ b/libmudflap/mf-runtime.c
@@ -35,7 +35,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 
 /* These attempt to coax various unix flavours to declare all our
    needed tidbits in the system headers.  */
-#if !defined(__FreeBSD__)
+#if !defined(__FreeBSD__) && !defined(__APPLE__)
 #define _POSIX_SOURCE
 #endif /* Some BSDs break <sys/socket.h> if this is defined. */
 #define _GNU_SOURCE