diff --git a/dlls/wintrust/asn.c b/dlls/wintrust/asn.c
index 09285bc0161..76ac8a81ec4 100644
--- a/dlls/wintrust/asn.c
+++ b/dlls/wintrust/asn.c
@@ -738,6 +738,15 @@ BOOL WINAPI WVTAsn1SpcIndirectDataContentEncode(DWORD dwCertEncodingType,
     return ret;
 }
 
+BOOL WINAPI WVTAsn1CatMemberInfoEncode(DWORD dwCertEncodingType,
+ LPCSTR lpszStructType, const void *pvStructInfo, BYTE *pbEncoded,
+ DWORD *pcbEncoded)
+{
+    FIXME("(0x%08x, %s, %p, %p, %p): stub\n", dwCertEncodingType,
+     debugstr_a(lpszStructType), pvStructInfo, pbEncoded, pcbEncoded);
+    return FALSE;
+}
+
 /* Gets the number of length bytes from the given (leading) length byte */
 #define GET_LEN_BYTES(b) ((b) <= 0x7f ? 1 : 1 + ((b) & 0x7f))
 
diff --git a/dlls/wintrust/wintrust.spec b/dlls/wintrust/wintrust.spec
index a9d0857ea92..35e1b2f56b8 100644
--- a/dlls/wintrust/wintrust.spec
+++ b/dlls/wintrust/wintrust.spec
@@ -87,7 +87,7 @@
 @ stub WTHelperOpenKnownStores
 @ stdcall WTHelperProvDataFromStateData(ptr)
 @ stub WVTAsn1CatMemberInfoDecode
-@ stub WVTAsn1CatMemberInfoEncode
+@ stdcall WVTAsn1CatMemberInfoEncode(long str ptr ptr ptr)
 @ stub WVTAsn1CatNameValueDecode
 @ stub WVTAsn1CatNameValueEncode
 @ stub WVTAsn1SpcFinancialCriteriaInfoDecode