diff --git a/sys/src/9/port/devpnp.c b/sys/src/9/port/devpnp.c
index 805c614ad..f0fcadcf5 100644
--- a/sys/src/9/port/devpnp.c
+++ b/sys/src/9/port/devpnp.c
@@ -544,7 +544,7 @@ pnpread(Chan *c, void *va, long n, vlong offset)
 		for(i=0; i<nelem(p->mem); i++){
 			if(p->mem[i].size == 0)
 				continue;
-			w = seprint(w, ebuf, " %d:%.8lux %d", i, p->mem[i].bar, p->mem[i].size);
+			w = seprint(w, ebuf, " %d:%.8llux %d", i, p->mem[i].bar, p->mem[i].size);
 		}
 		*w++ = '\n';
 		*w = '\0';