diff --git a/CHANGELOG b/CHANGELOG
index e16ac37..de407cf 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -123,3 +123,5 @@ WinDivert 1.4.0-rc
       for unmodified packets.
 WinDivert 1.4.1
     - Dual license WinDivert under LGPLv3 and GPLv2.
+WinDivert 1.4.2
+    - Add workaround for pseudo checksum issue (see #134).
diff --git a/VERSION b/VERSION
index 347f583..9df886c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.4.1
+1.4.2
diff --git a/dll/windivert.c b/dll/windivert.c
index 88c275e..cfcd346 100644
--- a/dll/windivert.c
+++ b/dll/windivert.c
@@ -514,6 +514,41 @@ extern HANDLE WinDivertOpen(const char *filter, WINDIVERT_LAYER layer,
     return handle;
 }
 
+/*
+ * Workaround for #134
+ */
+static void WinDivertFixChecksums(PVOID pPacket, UINT packetLen,
+    PWINDIVERT_ADDRESS addr)
+{
+    UINT64 flags =
+        WINDIVERT_HELPER_NO_IP_CHECKSUM |
+        WINDIVERT_HELPER_NO_TCP_CHECKSUM |
+        WINDIVERT_HELPER_NO_UDP_CHECKSUM;
+    BOOL calc = FALSE;
+    if (addr->PseudoIPChecksum != 0)
+    {
+        addr->PseudoIPChecksum = 0;
+        flags &= ~WINDIVERT_HELPER_NO_IP_CHECKSUM;
+        calc = TRUE;
+    }
+    if (addr->PseudoTCPChecksum != 0)
+    {
+        addr->PseudoTCPChecksum = 0;
+        flags &= ~WINDIVERT_HELPER_NO_TCP_CHECKSUM;
+        calc = TRUE;
+    }
+    if (addr->PseudoUDPChecksum != 0)
+    {
+        addr->PseudoUDPChecksum = 0;
+        flags &= ~WINDIVERT_HELPER_NO_UDP_CHECKSUM;
+        calc = TRUE;
+    }
+    if (calc)
+    {
+        WinDivertHelperCalcChecksums(pPacket, packetLen, addr, flags);
+    }
+}
+
 /*
  * Receive a WinDivert packet.
  */
@@ -554,6 +589,12 @@ extern BOOL WinDivertRecvEx(HANDLE handle, PVOID pPacket, UINT packetLen,
 extern BOOL WinDivertSend(HANDLE handle, PVOID pPacket, UINT packetLen,
     PWINDIVERT_ADDRESS addr, UINT *writelen)
 {
+    if (addr == NULL)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return FALSE;
+    }
+    WinDivertFixChecksums(pPacket, packetLen, addr);
     return WinDivertIoControl(handle, IOCTL_WINDIVERT_SEND, 0, (UINT64)addr,
         pPacket, packetLen, writelen);
 }
@@ -565,11 +606,12 @@ extern BOOL WinDivertSendEx(HANDLE handle, PVOID pPacket, UINT packetLen,
     UINT64 flags, PWINDIVERT_ADDRESS addr, UINT *writelen,
     LPOVERLAPPED overlapped)
 {
-    if (flags != 0)
+    if (flags != 0 || addr == NULL)
     {
         SetLastError(ERROR_INVALID_PARAMETER);
         return FALSE;
     }
+    WinDivertFixChecksums(pPacket, packetLen, addr);
     if (overlapped == NULL)
     {
         return WinDivertIoControl(handle, IOCTL_WINDIVERT_SEND, 0,