diff --git a/datamatrix/codesize.go b/datamatrix/codesize.go
index a949e59..c63eb8c 100644
--- a/datamatrix/codesize.go
+++ b/datamatrix/codesize.go
@@ -29,7 +29,15 @@ func (s *dmCodeSize) DataCodewords() int {
 	return ((s.MatrixColumns() * s.MatrixRows()) / 8) - s.ECCCount
 }
 
-func (s *dmCodeSize) DataCodewordsPerBlock() int {
+func (s *dmCodeSize) DataCodewordsForBlock(idx int) int {
+	if s.Rows == 144 && s.Columns == 144 {
+		// Special Case...
+		if idx < 8 {
+			return 156
+		} else {
+			return 155
+		}
+	}
 	return s.DataCodewords() / s.BlockCount
 }
 
diff --git a/datamatrix/errorcorrection.go b/datamatrix/errorcorrection.go
index 4c0bae6..ef5876b 100644
--- a/datamatrix/errorcorrection.go
+++ b/datamatrix/errorcorrection.go
@@ -54,7 +54,7 @@ func (ec *errorCorrection) calcECCBlock(data []byte, poly []int) []byte {
 }
 
 func (ec *errorCorrection) calcECC(data []byte, size *dmCodeSize) []byte {
-	buff := make([]byte, size.DataCodewordsPerBlock())
+
 	poly := ec.getPolynomial(size.ErrorCorrectionCodewordsPerBlock())
 
 	dataSize := len(data)
@@ -62,6 +62,9 @@ func (ec *errorCorrection) calcECC(data []byte, size *dmCodeSize) []byte {
 	data = append(data, make([]byte, size.ECCCount)...)
 
 	for block := 0; block < size.BlockCount; block++ {
+		dataCnt := size.DataCodewordsForBlock(block)
+
+		buff := make([]byte, dataCnt)
 		// copy the data for the current block to buff
 		j := 0
 		for i := block; i < dataSize; i += size.BlockCount {