diff --git a/src/main/java/com/sunyard/sge/database/SydApiSM4.java b/src/main/java/com/sunyard/sge/database/SydApiSM4.java
index cf06759..caa62b2 100644
--- a/src/main/java/com/sunyard/sge/database/SydApiSM4.java
+++ b/src/main/java/com/sunyard/sge/database/SydApiSM4.java
@@ -63,7 +63,7 @@ public class SydApiSM4 {
         } else {
             if (16 > pcData.length + sourceWrap.array().length) {
                 ByteBuffer bufferResult = ByteBuffer.allocate(sourceWrap.array().length + plength);
-                bufferResult.put(sourceWrap);
+                bufferResult.put(SydSM4Mac.bytebuffer2ByteArray(sourceWrap));
                 bufferResult.put(pcData);
                 sourceWrap = bufferResult;
             } else if ((pcData.length + sourceWrap.array().length) % 16 == 0) {