diff --git a/OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.c b/OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.c
index 1868c9fcaf..e52ec668f3 100644
--- a/OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.c
+++ b/OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.c
@@ -384,7 +384,7 @@ QemuLoadKernelImage (
     //
     // Drop the terminating NUL, convert to UTF-16.
     //
-    KernelLoadedImage->LoadOptionsSize = (CommandLineSize - 1) * 2;
+    KernelLoadedImage->LoadOptionsSize = (UINT32) ((CommandLineSize - 1) * 2);
   }
 
   QemuFwCfgSelectItem (QemuFwCfgItemInitrdSize);