diff --git a/mk2rbc/mk2rbc.go b/mk2rbc/mk2rbc.go
index d4da4f5..02b3d08 100644
--- a/mk2rbc/mk2rbc.go
+++ b/mk2rbc/mk2rbc.go
@@ -542,6 +542,12 @@
 	if strings.HasPrefix(name, "override ") {
 		return []starlarkNode{ctx.newBadNode(a, "cannot handle override directive")}
 	}
+	if name == ".KATI_READONLY" {
+		// Skip assignments to .KATI_READONLY. If it was in the output file, it
+		// would be an error because it would be sorted before the definition of
+		// the variable it's trying to make readonly.
+		return []starlarkNode{}
+	}
 
 	// Soong configuration
 	if strings.HasPrefix(name, soongNsPrefix) {
diff --git a/mk2rbc/mk2rbc_test.go b/mk2rbc/mk2rbc_test.go
index 6887ca4..9485a42 100644
--- a/mk2rbc/mk2rbc_test.go
+++ b/mk2rbc/mk2rbc_test.go
@@ -1531,6 +1531,20 @@
       cfg["PRODUCT_COPY_FILES"] += ("%s:foo/bar/%s" % (g.get("MY_OTHER_VAR", ""), x)).split()
 `,
 	},
+	{
+		desc:   ".KATI_READONLY",
+		mkname: "product.mk",
+		in: `
+MY_VAR := foo
+.KATI_READONLY := MY_VAR
+`,
+		expected: `load("//build/make/core:product_config.rbc", "rblf")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+  g["MY_VAR"] = "foo"
+`,
+	},
 }
 
 var known_variables = []struct {