--- /n/sources/plan9/sys/src/9/port/fault.c	Fri Aug 28 00:00:00 2026
+++ /sys/src/9/port/fault.c	Tue Sep 22 00:00:00 2026
@@ -183,7 +183,7 @@
 		 * process sharing it can have replaced the page in between,
 		 * and the flush it asked for came too early to reach here.
 		 */
-		if(*pg != mpg)
+		if(*pg != mpg || ((mmuphys & PTEWRITE) && mpg->ref > 1))
 			flushmmu();
 	}