diff --git a/reactos/dll/win32/advapi32/service/eventlog.c b/reactos/dll/win32/advapi32/service/eventlog.c
index 7a4acb5cc07..23b138b5f13 100644
--- a/reactos/dll/win32/advapi32/service/eventlog.c
+++ b/reactos/dll/win32/advapi32/service/eventlog.c
@@ -673,6 +673,12 @@ ReadEventLogA(IN HANDLE hEventLog,
         hEventLog, dwReadFlags, dwRecordOffset, lpBuffer,
         nNumberOfBytesToRead, pnBytesRead, pnMinNumberOfBytesNeeded);
 
+    if(!pnBytesRead || !pnMinNumberOfBytesNeeded)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return FALSE;
+    }
+
     /* If buffer is NULL set nNumberOfBytesToRead to 0 to prevent rpcrt4 from
        trying to access a null pointer */
     if (!lpBuffer)
@@ -737,6 +743,12 @@ ReadEventLogW(IN HANDLE hEventLog,
         hEventLog, dwReadFlags, dwRecordOffset, lpBuffer,
         nNumberOfBytesToRead, pnBytesRead, pnMinNumberOfBytesNeeded);
 
+    if(!pnBytesRead || !pnMinNumberOfBytesNeeded)
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return FALSE;
+    }
+
     /* If buffer is NULL set nNumberOfBytesToRead to 0 to prevent rpcrt4 from
        trying to access a null pointer */
     if (!lpBuffer)