diff --git a/lib/storage/block.go b/lib/storage/block.go
index 98b6211df..ee8e158fe 100644
--- a/lib/storage/block.go
+++ b/lib/storage/block.go
@@ -1,6 +1,7 @@
 package storage
 
 import (
+	"fmt"
 	"sync"
 	"sync/atomic"
 
@@ -9,11 +10,11 @@ import (
 )
 
 const (
-	// The maximum size of values in the block.
-	maxBlockSize = 64 * 1024
-
 	// The maximum number of rows per block.
 	maxRowsPerBlock = 8 * 1024
+
+	// The maximum size of values in the block.
+	maxBlockSize = 8 * maxRowsPerBlock
 )
 
 // Block represents a block of time series values for a single TSID.
@@ -259,7 +260,7 @@ func (b *Block) UnmarshalData() error {
 	}
 
 	if b.bh.RowsCount <= 0 {
-		logger.Panicf("BUG: RowsCount must be greater than 0; got %d", b.bh.RowsCount)
+		return fmt.Errorf("RowsCount must be greater than 0; got %d", b.bh.RowsCount)
 	}
 
 	var err error
@@ -281,7 +282,7 @@ func (b *Block) UnmarshalData() error {
 	b.valuesData = b.valuesData[:0]
 
 	if len(b.timestamps) != len(b.values) {
-		logger.Panicf("BUG: timestamps and values count mismatch; got %d vs %d", len(b.timestamps), len(b.values))
+		return fmt.Errorf("timestamps and values count mismatch; got %d vs %d", len(b.timestamps), len(b.values))
 	}
 
 	b.nextIdx = 0
diff --git a/lib/storage/block_header.go b/lib/storage/block_header.go
index cc266109b..38b49c44f 100644
--- a/lib/storage/block_header.go
+++ b/lib/storage/block_header.go
@@ -150,26 +150,33 @@ func (bh *blockHeader) Unmarshal(src []byte) ([]byte, error) {
 	bh.PrecisionBits = uint8(src[0])
 	src = src[1:]
 
-	if bh.RowsCount == 0 {
-		return src, fmt.Errorf("RowsCount in block header cannot be zero")
-	}
-	if err = encoding.CheckMarshalType(bh.TimestampsMarshalType); err != nil {
-		return src, fmt.Errorf("unsupported TimestampsMarshalType: %w", err)
-	}
-	if err = encoding.CheckMarshalType(bh.ValuesMarshalType); err != nil {
-		return src, fmt.Errorf("unsupported ValuesMarshalType: %w", err)
-	}
-	if err = encoding.CheckPrecisionBits(bh.PrecisionBits); err != nil {
-		return src, err
-	}
-	if bh.TimestampsBlockSize > 2*8*maxBlockSize {
-		return src, fmt.Errorf("too big TimestampsBlockSize; got %d; cannot exceed %d", bh.TimestampsBlockSize, 2*8*maxBlockSize)
-	}
-	if bh.ValuesBlockSize > 2*8*maxBlockSize {
-		return src, fmt.Errorf("too big ValuesBlockSize; got %d; cannot exceed %d", bh.ValuesBlockSize, 2*8*maxBlockSize)
-	}
+	err = bh.validate()
+	return src, err
+}
 
-	return src, nil
+func (bh *blockHeader) validate() error {
+	if bh.RowsCount == 0 {
+		return fmt.Errorf("RowsCount in block header cannot be zero")
+	}
+	if bh.RowsCount > 2*maxRowsPerBlock {
+		return fmt.Errorf("too big RowsCount; got %d; cannot exceed %d", bh.RowsCount, 2*maxRowsPerBlock)
+	}
+	if err := encoding.CheckMarshalType(bh.TimestampsMarshalType); err != nil {
+		return fmt.Errorf("unsupported TimestampsMarshalType: %w", err)
+	}
+	if err := encoding.CheckMarshalType(bh.ValuesMarshalType); err != nil {
+		return fmt.Errorf("unsupported ValuesMarshalType: %w", err)
+	}
+	if err := encoding.CheckPrecisionBits(bh.PrecisionBits); err != nil {
+		return err
+	}
+	if bh.TimestampsBlockSize > 2*maxBlockSize {
+		return fmt.Errorf("too big TimestampsBlockSize; got %d; cannot exceed %d", bh.TimestampsBlockSize, 2*maxBlockSize)
+	}
+	if bh.ValuesBlockSize > 2*maxBlockSize {
+		return fmt.Errorf("too big ValuesBlockSize; got %d; cannot exceed %d", bh.ValuesBlockSize, 2*maxBlockSize)
+	}
+	return nil
 }
 
 // unmarshalBlockHeaders unmarshals all the block headers from src,
diff --git a/lib/storage/block_header_test.go b/lib/storage/block_header_test.go
index ea5cdd669..cffcfcb7e 100644
--- a/lib/storage/block_header_test.go
+++ b/lib/storage/block_header_test.go
@@ -25,8 +25,8 @@ func TestBlockHeaderMarshalUnmarshal(t *testing.T) {
 		bh.MaxTimestamp = int64(i*2e3 + 3)
 		bh.TimestampsBlockOffset = uint64(i*12345 + 4)
 		bh.ValuesBlockOffset = uint64(i*3243 + 5)
-		bh.TimestampsBlockSize = uint32(i*892 + 6)
-		bh.ValuesBlockSize = uint32(i*894 + 7)
+		bh.TimestampsBlockSize = uint32((i*892 + 6) % maxBlockSize)
+		bh.ValuesBlockSize = uint32((i*894 + 7) % maxBlockSize)
 		bh.RowsCount = uint32(i*3 + 8)
 		bh.Scale = int16(i - 434 + 9)
 		bh.TimestampsMarshalType = encoding.MarshalType((i + 10) % 7)
diff --git a/lib/storage/metaindex_row.go b/lib/storage/metaindex_row.go
index ef93d5deb..162bbd94f 100644
--- a/lib/storage/metaindex_row.go
+++ b/lib/storage/metaindex_row.go
@@ -120,8 +120,8 @@ func (mr *metaindexRow) Unmarshal(src []byte) ([]byte, error) {
 	if mr.BlockHeadersCount <= 0 {
 		return src, fmt.Errorf("BlockHeadersCount must be greater than 0")
 	}
-	if mr.IndexBlockSize > 2*8*maxBlockSize {
-		return src, fmt.Errorf("too big IndexBlockSize; got %d; cannot exceed %d", mr.IndexBlockSize, 2*8*maxBlockSize)
+	if mr.IndexBlockSize > 2*maxBlockSize {
+		return src, fmt.Errorf("too big IndexBlockSize; got %d; cannot exceed %d", mr.IndexBlockSize, 2*maxBlockSize)
 	}
 
 	return src, nil
diff --git a/lib/storage/metaindex_row_test.go b/lib/storage/metaindex_row_test.go
index f55e755de..8f97995bd 100644
--- a/lib/storage/metaindex_row_test.go
+++ b/lib/storage/metaindex_row_test.go
@@ -91,8 +91,8 @@ func initTestMetaindexRow(mr *metaindexRow) {
 	if mr.BlockHeadersCount == 0 {
 		mr.BlockHeadersCount = 1
 	}
-	if mr.IndexBlockSize > 2*8*maxBlockSize {
-		mr.IndexBlockSize = 2 * 8 * maxBlockSize
+	if mr.IndexBlockSize > 2*maxBlockSize {
+		mr.IndexBlockSize = 2 * maxBlockSize
 	}
 }