diff --git a/win32ss/user/user32/misc/exticon.c b/win32ss/user/user32/misc/exticon.c
index 70e7d447a2b..587a32a297f 100644
--- a/win32ss/user/user32/misc/exticon.c
+++ b/win32ss/user/user32/misc/exticon.c
@@ -515,6 +515,7 @@ static UINT ICO_ExtractIconExW(
                     imageData = peimage + dataOffset;
 #ifdef __REACTOS__
                     /* Calculate the size of color table */
+                    ZeroMemory(&bi, sizeof(bi));
                     CopyMemory(&bi, imageData, sizeof(BITMAPCOREHEADER));
                     if (bi.biBitCount <= 8)
                     {