diff --git a/src/backend/storage/ipc/dsm.c b/src/backend/storage/ipc/dsm.c
index cab7ae74ca..cfbebeb31d 100644
--- a/src/backend/storage/ipc/dsm.c
+++ b/src/backend/storage/ipc/dsm.c
@@ -569,22 +569,20 @@ dsm_attach(dsm_handle h)
 	nitems = dsm_control->nitems;
 	for (i = 0; i < nitems; ++i)
 	{
-		/* If the reference count is 0, the slot is actually unused. */
-		if (dsm_control->item[i].refcnt == 0)
+		/*
+		 * If the reference count is 0, the slot is actually unused.  If the
+		 * reference count is 1, the slot is still in use, but the segment is
+		 * in the process of going away; even if the handle matches, another
+		 * slot may already have started using the same handle value by
+		 * coincidence so we have to keep searching.
+		 */
+		if (dsm_control->item[i].refcnt <= 1)
 			continue;
 
 		/* If the handle doesn't match, it's not the slot we want. */
 		if (dsm_control->item[i].handle != seg->handle)
 			continue;
 
-		/*
-		 * If the reference count is 1, the slot is still in use, but the
-		 * segment is in the process of going away.  Treat that as if we
-		 * didn't find a match.
-		 */
-		if (dsm_control->item[i].refcnt == 1)
-			break;
-
 		/* Otherwise we've found a match. */
 		dsm_control->item[i].refcnt++;
 		seg->control_slot = i;