diff --git a/include/log.h b/include/log.h
index 69eed96..14051cc 100644
--- a/include/log.h
+++ b/include/log.h
@@ -46,6 +46,8 @@ extern void log_crit(unsigned, const char* msg, ...);
 extern void log_debug(unsigned int, const char* msg, ...);
 extern void logmsg(const char* msg, ...);
 
+#include <unistd.h> /* Required for pid_t */
+
 extern pid_t log_pidinfo(struct autofs_point *ap, pid_t pid, char *label);
 
 #define debug(opt, msg, args...)	\