--- a/include/asterisk/compat.h
+++ b/include/asterisk/compat.h
@@ -130,14 +130,16 @@ void timersub(struct timeval *tvend, str
 
 #include <errno.h>
 
-#ifdef SOLARIS
+#ifndef __BEGIN_DECLS
 #define __BEGIN_DECLS
 #define __END_DECLS
+#endif
 
 #ifndef __P
 #define __P(p) p
 #endif
 
+#ifdef SOLARIS
 #include <alloca.h>
 #include <strings.h>
 #include <pthread.h>
--- a/utils/db1-ast/include/db.h
+++ b/utils/db1-ast/include/db.h
@@ -68,8 +68,11 @@ typedef	unsigned long long	u_int64_t;
 #endif /* __FreeBSD__ */
 #endif
 
-#ifdef SOLARIS
+#ifndef __P
 #define	__P(p) p
+#endif
+
+#ifndef __BEGIN_DECLS
 #define __BEGIN_DECLS
 #define __END_DECLS
 #endif