diff --git a/fragment.go b/fragment.go
index 81f644e3c..550e4afb7 100644
--- a/fragment.go
+++ b/fragment.go
@@ -556,6 +556,17 @@ func (f *fragment) unprotectedSetBit(rowID, columnID uint64) (changed bool, err
 
 	// Don't update the cache if nothing changed.
 	if !changed {
+		row, _ := f.rowCache.Fetch(rowID)
+		if row != nil && !row.Includes(columnID) {
+			// paranoia time. It should be impossible for the
+			// rowCache to have an entry which lacks a bit which is
+			// in storage, but we've seen some behavior which
+			// indicated this is happening... so we'll check and
+			// clear the rowCache rather than risking returning
+			// inconsistent data in a query.
+			f.Logger.Printf("INCONSISTENT: index:%s field:%s found bit row/col %d/%d not in cache after in storage; dropping cached row, consider restarting Pilosa.", f.index, f.field, rowID, columnID)
+			f.rowCache.Add(rowID, nil)
+		}
 		return changed, nil
 	}
 
diff --git a/roaring/roaring.go b/roaring/roaring.go
index 22d2821db..fef47bfda 100644
--- a/roaring/roaring.go
+++ b/roaring/roaring.go
@@ -21,6 +21,7 @@ import (
 	"hash/fnv"
 	"io"
 	"math/bits"
+	"os"
 	"reflect"
 	"sort"
 	"unsafe"
@@ -3190,6 +3191,9 @@ func (c *Container) arrayRemove(v uint16) (*Container, bool) {
 	}
 	// removing the last item? we can just return the empty container.
 	if c.N() == 1 {
+		if c.flags&(flagFrozen|flagMapped) != 0 {
+			fmt.Fprintf(os.Stderr, "INCONSISTENT: array remove of %d setting N in another container\n", v)
+		}
 		c.n = 0
 		return nil, true
 	}
@@ -3207,6 +3211,9 @@ func (c *Container) bitmapRemove(v uint16) (*Container, bool) {
 	}
 	// removing the last item? we can just return the empty container.
 	if c.N() == 1 {
+		if c.flags&(flagFrozen|flagMapped) != 0 {
+			fmt.Fprintf(os.Stderr, "INCONSISTENT: bitmap remove of %d setting N in another container\n", v)
+		}
 		c.n = 0
 		return nil, true
 	}
@@ -3233,6 +3240,9 @@ func (c *Container) runRemove(v uint16) (*Container, bool) {
 	}
 	// removing the last item? we can just return the empty container.
 	if c.N() == 1 {
+		if c.flags&(flagFrozen|flagMapped) != 0 {
+			fmt.Fprintf(os.Stderr, "INCONSISTENT: run remove of %d setting N in another container\n", v)
+		}
 		c.n = 0
 		return nil, true
 	}
@@ -4292,6 +4302,9 @@ func unionArrayArrayInPlace(a, b *Container) *Container {
 			// ... but we also want to be sure we don't end up
 			// copying in a mapped object into our not-mapped
 			// object.
+			if !b.Mapped() {
+				fmt.Fprintf(os.Stderr, "INCONSISTENT: unionArrayArray referencing array of %d elements\n", b.N())
+			}
 			a.setArrayMaybeCopy(b.array(), b.Mapped())
 			return a.optimize()
 		}
diff --git a/roaring/roaring_helpers_test.go b/roaring/roaring_helpers_test.go
index 41d4059fb..c07e530e0 100644
--- a/roaring/roaring_helpers_test.go
+++ b/roaring/roaring_helpers_test.go
@@ -251,12 +251,12 @@ type testOp struct {
 func doContainer(typ byte, data interface{}) *Container {
 	switch typ {
 	case containerArray:
-		return NewContainerArray(data.([]uint16))
+		return NewContainerArray(data.([]uint16)).Freeze()
 	case containerBitmap:
-		c := NewContainerBitmap(-1, data.([]uint64))
+		c := NewContainerBitmap(-1, data.([]uint64)).Freeze()
 		return c
 	case containerRun:
-		return NewContainerRun(data.([]interval16))
+		return NewContainerRun(data.([]interval16)).Freeze()
 	}
 	return nil
 }