diff --git a/chain/exchange/client.go b/chain/exchange/client.go
index 57563d5b2..20a130c1d 100644
--- a/chain/exchange/client.go
+++ b/chain/exchange/client.go
@@ -210,31 +210,9 @@ func (c *client) processResponse(req *Request, res *Response) (*validatedRespons
 			// If the headers were also returned check that the compression
 			// indexes are valid before `toFullTipSets()` is called by the
 			// consumer.
-			for tipsetIdx := 0; tipsetIdx < resLength; tipsetIdx++ {
-				msgs := res.Chain[tipsetIdx].Messages
-				blocksNum := len(res.Chain[tipsetIdx].Blocks)
-				if len(msgs.BlsIncludes) != blocksNum {
-					return nil, xerrors.Errorf("BlsIncludes (%d) does not match number of blocks (%d)",
-						len(msgs.BlsIncludes), blocksNum)
-				}
-				if len(msgs.SecpkIncludes) != blocksNum {
-					return nil, xerrors.Errorf("SecpkIncludes (%d) does not match number of blocks (%d)",
-						len(msgs.SecpkIncludes), blocksNum)
-				}
-				for blockIdx := 0; blockIdx < blocksNum; blockIdx++ {
-					for _, mi := range msgs.BlsIncludes[blockIdx] {
-						if int(mi) >= len(msgs.Bls) {
-							return nil, xerrors.Errorf("index in BlsIncludes (%d) exceeds number of messages (%d)",
-								mi, len(msgs.Bls))
-						}
-					}
-					for _, mi := range msgs.SecpkIncludes[blockIdx] {
-						if int(mi) >= len(msgs.Secpk) {
-							return nil, xerrors.Errorf("index in SecpkIncludes (%d) exceeds number of messages (%d)",
-								mi, len(msgs.Secpk))
-						}
-					}
-				}
+			err := c.validateCompressedIndices(res.Chain)
+			if err != nil {
+				return nil, err
 			}
 		}
 	}
@@ -242,6 +220,42 @@ func (c *client) processResponse(req *Request, res *Response) (*validatedRespons
 	return validRes, nil
 }
 
+func (c *client) validateCompressedIndices(chain []*BSTipSet) error {
+	resLength := len(chain)
+	for tipsetIdx := 0; tipsetIdx < resLength; tipsetIdx++ {
+		msgs := chain[tipsetIdx].Messages
+		blocksNum := len(chain[tipsetIdx].Blocks)
+
+		if len(msgs.BlsIncludes) != blocksNum {
+			return xerrors.Errorf("BlsIncludes (%d) does not match number of blocks (%d)",
+				len(msgs.BlsIncludes), blocksNum)
+		}
+
+		if len(msgs.SecpkIncludes) != blocksNum {
+			return xerrors.Errorf("SecpkIncludes (%d) does not match number of blocks (%d)",
+				len(msgs.SecpkIncludes), blocksNum)
+		}
+
+		for blockIdx := 0; blockIdx < blocksNum; blockIdx++ {
+			for _, mi := range msgs.BlsIncludes[blockIdx] {
+				if int(mi) >= len(msgs.Bls) {
+					return xerrors.Errorf("index in BlsIncludes (%d) exceeds number of messages (%d)",
+						mi, len(msgs.Bls))
+				}
+			}
+
+			for _, mi := range msgs.SecpkIncludes[blockIdx] {
+				if int(mi) >= len(msgs.Secpk) {
+					return xerrors.Errorf("index in SecpkIncludes (%d) exceeds number of messages (%d)",
+						mi, len(msgs.Secpk))
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
 // GetBlocks implements Client.GetBlocks(). Refer to the godocs there.
 func (c *client) GetBlocks(ctx context.Context, tsk types.TipSetKey, count int) ([]*types.TipSet, error) {
 	ctx, span := trace.StartSpan(ctx, "bsync.GetBlocks")