diff --git a/aucat/aucat.c b/aucat/aucat.c
index 66c7284..d021a1d 100644
--- a/aucat/aucat.c
+++ b/aucat/aucat.c
@@ -69,9 +69,9 @@
 #endif
 
 #ifdef DEBUG
-int debug_level = 0;
+volatile sig_atomic_t debug_level = 0;
 #endif
-volatile int quit_flag = 0;
+volatile sig_atomic_t quit_flag = 0;
 
 /*
  * SIGINT handler, it raises the quit flag. If the flag is already set,
diff --git a/aucat/conf.h b/aucat/conf.h
index 92bdef7..26f39ee 100644
--- a/aucat/conf.h
+++ b/aucat/conf.h
@@ -27,7 +27,7 @@
  * 3 - structural changes (new aproc structures and files stream params changes)
  * 4 - data blocks and messages
  */
-extern int debug_level;
+extern volatile sig_atomic_t debug_level;
 #endif
 
 /*
diff --git a/aucat/listen.c b/aucat/listen.c
index ca830d5..c0cc63a 100644
--- a/aucat/listen.c
+++ b/aucat/listen.c
@@ -16,6 +16,7 @@
  */
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/signal.h>
 #include <sys/stat.h>
 #include <sys/un.h>
 
diff --git a/aucat/pipe.c b/aucat/pipe.c
index 065f6f0..8390092 100644
--- a/aucat/pipe.c
+++ b/aucat/pipe.c
@@ -16,6 +16,7 @@
 
 #include <sys/time.h>
 #include <sys/types.h>
+#include <sys/signal.h>
 
 #include <err.h>
 #include <errno.h>