diff --git a/dll/win32/kernel32/client/file/volume.c b/dll/win32/kernel32/client/file/volume.c
index 90016b8e086..ba0ef82f5dd 100644
--- a/dll/win32/kernel32/client/file/volume.c
+++ b/dll/win32/kernel32/client/file/volume.c
@@ -253,6 +253,10 @@ GetVolumeInformationW(IN LPCWSTR lpRootPathName,
         RootPathName = lpRootPathName;
     }
 
+    /* Convert length to bytes */
+    nVolumeNameSize *= sizeof(WCHAR);
+    nFileSystemNameSize *= sizeof(WCHAR);
+
     /* Convert to NT name */
     if (!RtlDosPathNameToNtPathName_U(RootPathName, &NtPathName, NULL, NULL))
     {