diff --git a/sys/src/9/port/devmnt.c b/sys/src/9/port/devmnt.c
index 63f235ebb..9f6728a4b 100644
--- a/sys/src/9/port/devmnt.c
+++ b/sys/src/9/port/devmnt.c
@@ -706,7 +706,7 @@ mntrdwr(int type, Chan *c, void *buf, long n, vlong off)
 		if(nreq > c->iounit)
 			nreq = c->iounit;
 
-		if(type == Tread) {
+		if(type == Tread && (c->flag&CCACHE) != 0) {
 			nr = cread(c, (uchar*)uba, nreq, off);
 			if(nr > 0) {
 				nreq = nr;
diff --git a/sys/src/9/port/segment.c b/sys/src/9/port/segment.c
index 987f984cc..d7124caef 100644
--- a/sys/src/9/port/segment.c
+++ b/sys/src/9/port/segment.c
@@ -232,6 +232,9 @@ attachimage(int type, Chan *c, uintptr base, ulong len)
 {
 	Image *i, **l;
 
+	c->flag &= ~CCACHE;
+	cclunk(c);
+
 	lock(&imagealloc);
 
 	/*
@@ -272,7 +275,6 @@ found:
 	unlock(&imagealloc);
 	if(i->c == nil){
 		i->c = c;
-		c->flag &= ~CCACHE;
 		incref(c);
 	}
 
diff --git a/sys/src/9/port/swap.c b/sys/src/9/port/swap.c
index c5e249732..9d492257e 100644
--- a/sys/src/9/port/swap.c
+++ b/sys/src/9/port/swap.c
@@ -424,6 +424,7 @@ setswapchan(Chan *c)
 		}
 	}
 	c->flag &= ~CCACHE;
+	cclunk(c);
 	swapimage.c = c;
 	poperror();
 }