diff --git a/compiler.h b/compiler.h
new file mode 100755
index 0000000..137e9e1
--- /dev/null
+++ b/compiler.h
@@ -0,0 +1,19 @@
+/*
+ * Asterisk -- A telephony toolkit for Linux.
+ *
+ * Compiler-specific macros and other items
+ *
+ * Copyright (C) 2005, Digium, Inc.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License
+ */
+
+#ifndef _ASTERISK_COMPILER_H
+#define _ASTERISK_COMPILER_H
+
+#if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
+#define __builtin_expect(exp, c) (exp)
+#endif
+
+#endif /* _ASTERISK_COMPILER_H */
diff --git a/copy_string.c b/copy_string.c
index 2bb0019..a96f160 100755
--- a/copy_string.c
+++ b/copy_string.c
@@ -26,6 +26,7 @@
 #include <unistd.h>
 #include <stdlib.h>
 
+#include "compiler.h"
 #include "libpri.h"
 #include "pri_internal.h"