diff --git a/rbf/cursorx.go b/rbf/cursorx.go
index 0ca291ff1..f1c8f338a 100644
--- a/rbf/cursorx.go
+++ b/rbf/cursorx.go
@@ -197,9 +197,9 @@ func intoContainer(l leafCell, tx *Tx, replacing *roaring.Container, target []by
 		}
 		c = roaring.RemakeContainerBitmap(replacing, cloneMaybe)
 	case ContainerTypeBitmap:
-		c = roaring.RemakeContainerBitmap(replacing, toArray64(cpMaybe))
+		c = roaring.RemakeContainerBitmapN(replacing, toArray64(cpMaybe), int32(l.BitN))
 	case ContainerTypeRLE:
-		c = roaring.RemakeContainerRun(replacing, toInterval16(cpMaybe))
+		c = roaring.RemakeContainerRunN(replacing, toInterval16(cpMaybe), int32(l.BitN))
 	}
 	// Note: If the "roaringparanoia" build tag isn't set, this
 	// should be optimized away entirely. Otherwise it's moderately
diff --git a/roaring/container_stash.go b/roaring/container_stash.go
index 2cde05743..7dd6eae83 100644
--- a/roaring/container_stash.go
+++ b/roaring/container_stash.go
@@ -125,6 +125,8 @@ func NewContainer() *Container {
 	return NewContainerArray(nil)
 }
 
+// RemakeContainerBitmap overwrites the contents of c, which must not be
+// frozen, with a provided bitmap, and computes a correct N.
 func RemakeContainerBitmap(c *Container, bitmap []uint64) *Container {
 	*c = Container{typeID: ContainerBitmap}
 	c.setBitmap(bitmap)
@@ -132,15 +134,41 @@ func RemakeContainerBitmap(c *Container, bitmap []uint64) *Container {
 	return c
 }
 
+// RemakeContainerBitmapN uses the provided n instead of counting bits. The
+// provided container must not be frozen.
+func RemakeContainerBitmapN(c *Container, bitmap []uint64, n int32) *Container {
+	*c = Container{typeID: ContainerBitmap}
+	c.setBitmap(bitmap)
+	c.n = n
+	return c
+}
+
+// RemakeContainerArray populates c with an array container using the provided
+// array. It must not be used on a frozen container.
 func RemakeContainerArray(c *Container, array []uint16) *Container {
 	*c = Container{typeID: ContainerArray}
 	c.setArray(array)
 	return c
 }
 
+// RemakeContainerRun repopulates c with the provided intervals. c must not
+// be frozen.
 func RemakeContainerRun(c *Container, intervals []Interval16) *Container {
 	*c = Container{typeID: ContainerRun}
 	c.setRuns(intervals)
+	c.n = 0
+	for _, r := range intervals {
+		c.n += int32(r.Last - r.Start + 1)
+	}
+	return c
+}
+
+// RemakeContainerRunN repopulates c with the provided intervals, but
+// assumes the provided n is accurate. c must not be frozen.
+func RemakeContainerRunN(c *Container, intervals []Interval16, n int32) *Container {
+	*c = Container{typeID: ContainerRun}
+	c.setRuns(intervals)
+	c.n = n
 	return c
 }