diff --git a/fcntl.c b/fcntl.c
index b30fc17..e2a76f9 100644
--- a/fcntl.c
+++ b/fcntl.c
@@ -140,7 +140,8 @@
 	case F_GETFD:
 		if (entering(tcp) || syserror(tcp) || tcp->u_rval == 0)
 			return 0;
-		tcp->auxstr = sprintflags("flags ", fdflags, tcp->u_rval);
+		tcp->auxstr = sprintflags("flags ", fdflags,
+					  (unsigned long) tcp->u_rval);
 		return RVAL_HEX | RVAL_STR;
 	case F_GETFL:
 		if (entering(tcp) || syserror(tcp))
@@ -173,7 +174,8 @@
 	case F_GET_SEALS:
 		if (entering(tcp) || syserror(tcp) || tcp->u_rval == 0)
 			return 0;
-		tcp->auxstr = sprintflags("seals ", f_seals, tcp->u_rval);
+		tcp->auxstr = sprintflags("seals ", f_seals,
+					  (unsigned long) tcp->u_rval);
 		return RVAL_HEX | RVAL_STR;
 	case F_GETSIG:
 		if (entering(tcp) || syserror(tcp) || tcp->u_rval == 0)
diff --git a/membarrier.c b/membarrier.c
index 485c62a..3bc5764 100644
--- a/membarrier.c
+++ b/membarrier.c
@@ -43,6 +43,7 @@
 	if (syserror(tcp) || !tcp->u_rval)
 		return 0;
 
-	tcp->auxstr = sprintflags("", membarrier_cmds, tcp->u_rval);
+	tcp->auxstr = sprintflags("", membarrier_cmds,
+				  (unsigned long) tcp->u_rval);
 	return RVAL_HEX | RVAL_STR;
 }
diff --git a/poll.c b/poll.c
index afe0493..f116cef 100644
--- a/poll.c
+++ b/poll.c
@@ -112,7 +112,8 @@
 		char fdstr[sizeof(fmt) + sizeof(int) * 3];
 		sprintf(fdstr, fmt, fds.fd);
 
-		const char *flagstr = sprintflags("", pollflags, fds.revents);
+		const char *flagstr = sprintflags("", pollflags,
+						  (unsigned short) fds.revents);
 
 		if (outptr + strlen(fdstr) + strlen(flagstr) + 1 >=
 		    end_outstr - (2 + 2 * sizeof(long) + sizeof(", ], ..."))) {
diff --git a/prctl.c b/prctl.c
index 4ddd0b9..a0b4e96 100644
--- a/prctl.c
+++ b/prctl.c
@@ -122,7 +122,8 @@
 			break;
 		if (syserror(tcp) || tcp->u_rval == 0)
 			return 0;
-		tcp->auxstr = sprintflags("", secbits, tcp->u_rval);
+		tcp->auxstr = sprintflags("", secbits,
+					  (unsigned long) tcp->u_rval);
 		return RVAL_STR;
 
 	case PR_GET_TID_ADDRESS: