diff --git a/compat/compat.h.in b/compat/compat.h.in
index 3a14969..d84eeb4 100644
--- a/compat/compat.h.in
+++ b/compat/compat.h.in
@@ -61,6 +61,7 @@
 #cmakedefine HAVE_PTHREAD_MUTEX_TIMEDLOCK
 #cmakedefine HAVE_TM_GMTOFF
 #cmakedefine HAVE_TIME_H_TIMEZONE
+#cmakedefine HAVE_REALPATH
 
 #ifndef bswap64
 #define bswap64(val) \
@@ -158,4 +159,8 @@
 int pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *abstime);
 #endif
 
+#ifndef HAVE_REALPATH
+char *realpath(const char *path, char *resolved_path);
+#endif
+
 #endif /* _COMPAT_H_ */