diff --git a/src/internal.c b/src/internal.c
index a3358188..37f3adec 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -6267,6 +6267,15 @@ static int BundlePacket(WOLFSSH* ssh)
 }
 
 
+static void PurgePacket(WOLFSSH* ssh)
+{
+    ssh->packetStartIdx = 0;
+    ssh->outputBuffer.idx = 0;
+    ssh->outputBuffer.plainSz = 0;
+    ShrinkBuffer(&ssh->outputBuffer, 1);
+}
+
+
 static INLINE void CopyNameList(byte* buf, word32* idx,
                                                 const char* src, word32 srcSz)
 {
@@ -6505,6 +6514,9 @@ int SendKexInit(WOLFSSH* ssh)
     if (ret == WS_SUCCESS)
         ret = wolfSSH_SendPacket(ssh);
 
+    if (ret != WS_WANT_WRITE && ret != WS_SUCCESS)
+        PurgePacket(ssh);
+
     WLOG(WS_LOG_DEBUG, "Leaving SendKexInit(), ret = %d", ret);
     return ret;
 }
@@ -7238,6 +7250,9 @@ int SendKexDhReply(WOLFSSH* ssh)
     if (ret == WS_SUCCESS)
         ret = SendNewKeys(ssh);
 
+    if (ret != WS_WANT_WRITE && ret != WS_SUCCESS)
+        PurgePacket(ssh);
+
     WLOG(WS_LOG_DEBUG, "Leaving SendKexDhReply(), ret = %d", ret);
 #ifdef WOLFSSH_SMALL_STACK
     if (sigKeyBlock_ptr)
@@ -8600,6 +8615,9 @@ int SendUserAuthRequest(WOLFSSH* ssh, byte authId, int addSig)
     if (ret == WS_SUCCESS)
         ret = wolfSSH_SendPacket(ssh);
 
+    if (ret != WS_WANT_WRITE && ret != WS_SUCCESS)
+        PurgePacket(ssh);
+
     ForceZero(&authData, sizeof(WS_UserAuthData));
     WLOG(WS_LOG_DEBUG, "Leaving SendUserAuthRequest(), ret = %d", ret);
 #ifdef WOLFSSH_SMALL_STACK