diff --git a/datasquare.go b/datasquare.go
index 96fadb7..5c0a3cf 100644
--- a/datasquare.go
+++ b/datasquare.go
@@ -231,7 +231,7 @@ func (ds *dataSquare) getColRoot(y uint) []byte {
 	return tree.Root()
 }
 
-// getCell returns a single chunk at a specific cell.
+// getCell returns a copy of single chunk at a specific cell.
 func (ds *dataSquare) getCell(x uint, y uint) []byte {
 	if ds.squareRow[x][y] == nil {
 		return nil
diff --git a/extendeddatacrossword.go b/extendeddatacrossword.go
index 8a97484..e9c9558 100644
--- a/extendeddatacrossword.go
+++ b/extendeddatacrossword.go
@@ -355,7 +355,7 @@ func (eds *ExtendedDataSquare) computeSharesRoot(shares [][]byte, i uint) []byte
 
 func (eds *ExtendedDataSquare) rowRangeNoMissingData(r, start, end uint) bool {
 	for c := start; c <= end && c < eds.width; c++ {
-		if eds.getCell(r, c) == nil {
+		if eds.squareRow[r][c] == nil {
 			return false
 		}
 	}
@@ -364,7 +364,7 @@ func (eds *ExtendedDataSquare) rowRangeNoMissingData(r, start, end uint) bool {
 
 func (eds *ExtendedDataSquare) colRangeNoMissingData(c, start, end uint) bool {
 	for r := start; r <= end && r < eds.width; r++ {
-		if eds.getCell(r, c) == nil {
+		if eds.squareRow[r][c]  == nil {
 			return false
 		}
 	}