diff --git a/cc/config/x86_windows_host.go b/cc/config/x86_windows_host.go
index 6300a1bcf..e23c0a08f 100644
--- a/cc/config/x86_windows_host.go
+++ b/cc/config/x86_windows_host.go
@@ -140,6 +140,9 @@ func init() {
 	pctx.StaticVariable("WindowsX8664ClangCppflags", strings.Join(windowsX8664ClangCppflags, " "))
 
 	pctx.StaticVariable("WindowsIncludeFlags", strings.Join(windowsIncludeFlags, " "))
+	// Yasm flags
+	pctx.StaticVariable("WindowsX86YasmFlags", "-f win32 -m x86")
+	pctx.StaticVariable("WindowsX8664YasmFlags", "-f win64 -m amd64")
 }
 
 type toolchainWindows struct {
@@ -228,6 +231,14 @@ func (t *toolchainWindowsX8664) ClangLldflags() string {
 	return "${config.WindowsClangLldflags} ${config.WindowsX8664ClangLldflags}"
 }
 
+func (t *toolchainWindowsX86) YasmFlags() string {
+	return "${config.WindowsX86YasmFlags}"
+}
+
+func (t *toolchainWindowsX8664) YasmFlags() string {
+	return "${config.WindowsX8664YasmFlags}"
+}
+
 func (t *toolchainWindows) ShlibSuffix() string {
 	return ".dll"
 }