diff --git a/dlls/crypt32/msg.c b/dlls/crypt32/msg.c
index 6e7840981a3..ad4ba959d22 100644
--- a/dlls/crypt32/msg.c
+++ b/dlls/crypt32/msg.c
@@ -1259,7 +1259,8 @@ static HCRYPTMSG CSignedEncodeMsg_Open(DWORD dwFlags,
         SetLastError(E_INVALIDARG);
         return NULL;
     }
-    if (info->cbSize == sizeof(CMSG_SIGNED_ENCODE_INFO_WITH_CMS))
+    if (info->cbSize == sizeof(CMSG_SIGNED_ENCODE_INFO_WITH_CMS) &&
+     info->rgAttrCertEncoded)
     {
         FIXME("CMSG_SIGNED_ENCODE_INFO with CMS fields unsupported\n");
         return NULL;
diff --git a/dlls/crypt32/tests/msg.c b/dlls/crypt32/tests/msg.c
index b8c40f968f0..0f691902079 100644
--- a/dlls/crypt32/tests/msg.c
+++ b/dlls/crypt32/tests/msg.c
@@ -24,6 +24,7 @@
 #include <winbase.h>
 #include <winerror.h>
 #define CMSG_SIGNER_ENCODE_INFO_HAS_CMS_FIELDS
+#define CMSG_SIGNED_ENCODE_INFO_HAS_CMS_FIELDS
 #include <wincrypt.h>
 
 #include "wine/test.h"