diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 4cd6d6dfbb9..b215b77fee2 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -1594,7 +1594,7 @@ pq_setkeepaliveswin32(Port *port, int idle, int interval)
 		!= 0)
 	{
 		ereport(LOG,
-				(errmsg("WSAIoctl(%s) failed: %ui",
+				(errmsg("WSAIoctl(%s) failed: %d",
 						"SIO_KEEPALIVE_VALS", WSAGetLastError())));
 		return STATUS_ERROR;
 	}
diff --git a/src/backend/port/win32/socket.c b/src/backend/port/win32/socket.c
index a8012c2798d..af151e84709 100644
--- a/src/backend/port/win32/socket.c
+++ b/src/backend/port/win32/socket.c
@@ -635,7 +635,7 @@ pgwin32_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, c
 		{
 			ZeroMemory(&resEvents, sizeof(resEvents));
 			if (WSAEnumNetworkEvents(sockets[i], events[i], &resEvents) != 0)
-				elog(ERROR, "failed to enumerate network events: error code %u",
+				elog(ERROR, "failed to enumerate network events: error code %d",
 					 WSAGetLastError());
 			/* Read activity? */
 			if (readfds && FD_ISSET(sockets[i], readfds))
diff --git a/src/backend/storage/ipc/latch.c b/src/backend/storage/ipc/latch.c
index 5f3318fa8f1..e91755c7042 100644
--- a/src/backend/storage/ipc/latch.c
+++ b/src/backend/storage/ipc/latch.c
@@ -1280,11 +1280,11 @@ WaitEventAdjustWin32(WaitEventSet *set, WaitEvent *event)
 		{
 			*handle = WSACreateEvent();
 			if (*handle == WSA_INVALID_EVENT)
-				elog(ERROR, "failed to create event for socket: error code %u",
+				elog(ERROR, "failed to create event for socket: error code %d",
 					 WSAGetLastError());
 		}
 		if (WSAEventSelect(event->fd, *handle, flags) != 0)
-			elog(ERROR, "failed to set up event for socket: error code %u",
+			elog(ERROR, "failed to set up event for socket: error code %d",
 				 WSAGetLastError());
 
 		Assert(event->fd != PGINVALID_SOCKET);
@@ -1971,7 +1971,7 @@ WaitEventSetWaitBlock(WaitEventSet *set, int cur_timeout,
 
 		ZeroMemory(&resEvents, sizeof(resEvents));
 		if (WSAEnumNetworkEvents(cur_event->fd, handle, &resEvents) != 0)
-			elog(ERROR, "failed to enumerate network events: error code %u",
+			elog(ERROR, "failed to enumerate network events: error code %d",
 				 WSAGetLastError());
 		if ((cur_event->events & WL_SOCKET_READABLE) &&
 			(resEvents.lNetworkEvents & FD_READ))
diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index aa654dd6a8e..96b9edf1256 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -1985,7 +1985,7 @@ setKeepalivesWin32(PGconn *conn)
 		!= 0)
 	{
 		appendPQExpBuffer(&conn->errorMessage,
-						  libpq_gettext("WSAIoctl(SIO_KEEPALIVE_VALS) failed: %ui\n"),
+						  libpq_gettext("WSAIoctl(SIO_KEEPALIVE_VALS) failed: %d\n"),
 						  WSAGetLastError());
 		return 0;
 	}