diff --git a/include/minix/com.h b/include/minix/com.h
index f9cb110ed..2f85d774f 100644
--- a/include/minix/com.h
+++ b/include/minix/com.h
@@ -586,7 +586,6 @@
 
 /* Field names for system signals (sent by a signal manager). */
 #define SIGS_SIGNAL_RECEIVED (COMMON_RQ_BASE+0)
-#	define SIGS_SIG_NUM      m2_i1
 
 /* Common request to all processes: gcov data. */
 #define COMMON_REQ_GCOV_DATA (COMMON_RQ_BASE+1)
diff --git a/include/minix/ipc.h b/include/minix/ipc.h
index 4f3e87607..aa46868e1 100644
--- a/include/minix/ipc.h
+++ b/include/minix/ipc.h
@@ -124,6 +124,13 @@ typedef struct {
 } mess_lsys_krn_readbios;
 _ASSERT_MSG_SIZE(mess_lsys_krn_readbios);
 
+typedef struct {
+	int num;
+
+	uint8_t padding[52];
+} mess_pm_lsys_sigs_signal;
+_ASSERT_MSG_SIZE(mess_pm_lsys_sigs_signal);
+
 typedef struct {
 	off_t offset;
 	void *addr;
@@ -1962,6 +1969,7 @@ typedef struct {
 		mess_sigcalls		m_sigcalls;
 
 		mess_lsys_krn_readbios	m_lsys_krn_readbios;
+		mess_pm_lsys_sigs_signal m_pm_lsys_sigs_signal;
 		mess_input_tty_event	m_input_tty_event;
 
 		mess_krn_lsys_schedule	m_krn_lsys_schedule;
diff --git a/lib/libsys/sef_signal.c b/lib/libsys/sef_signal.c
index d26ec47fe..0a904ee08 100644
--- a/lib/libsys/sef_signal.c
+++ b/lib/libsys/sef_signal.c
@@ -114,7 +114,7 @@ int do_sef_signal_request(message *m_ptr)
   }
   else {
       /* Handle system signals from a signal manager. */
-      signo = m_ptr->SIGS_SIG_NUM;
+      signo = m_ptr->m_pm_lsys_sigs_signal.num;
 
       /* Debug. */
 #if SEF_SIGNAL_DEBUG
diff --git a/servers/pm/signal.c b/servers/pm/signal.c
index 304fd6085..6c18f3f18 100644
--- a/servers/pm/signal.c
+++ b/servers/pm/signal.c
@@ -464,7 +464,7 @@ int ksig;			/* non-zero means signal comes from kernel  */
 		/* Translate every non-termination sys signal into a message. */
 		message m;
 		m.m_type = SIGS_SIGNAL_RECEIVED;
-		m.SIGS_SIG_NUM = signo;
+		m.m_pm_lsys_sigs_signal.num = signo;
 		asynsend3(rmp->mp_endpoint, &m, AMF_NOREPLY);
 	}
 	else {
diff --git a/servers/rs/main.c b/servers/rs/main.c
index 5c5cd154f..6b7e032a7 100644
--- a/servers/rs/main.c
+++ b/servers/rs/main.c
@@ -545,7 +545,7 @@ static int sef_cb_signal_manager(endpoint_t target, int signo)
 
   /* Translate every non-termination signal into a message. */
   m.m_type = SIGS_SIGNAL_RECEIVED;
-  m.SIGS_SIG_NUM = signo;
+  m.m_pm_lsys_sigs_signal.num = signo;
   asynsend3(rpub->endpoint, &m, AMF_NOREPLY);
 
   return OK; /* signal has been delivered */