diff --git a/apex/apex_test.go b/apex/apex_test.go
index 532a7aa..321883f 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -5574,7 +5574,7 @@
 		}
 		`, withManifestPackageNameOverrides([]string{"AppFoo:com.android.foo"}))
 
-	bundleConfigRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Description("Bundle Config")
+	bundleConfigRule := ctx.ModuleForTests("myapex", "android_common_myapex_image").Output("bundle_config.json")
 	content := bundleConfigRule.Args["content"]
 
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
@@ -5600,7 +5600,7 @@
 			set: "AppSet.apks",
 		}`)
 	mod := ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	bundleConfigRule := mod.Description("Bundle Config")
+	bundleConfigRule := mod.Output("bundle_config.json")
 	content := bundleConfigRule.Args["content"]
 	ensureContains(t, content, `"compression":{"uncompressed_glob":["apex_payload.img","apex_manifest.*"]}`)
 	s := mod.Rule("apexRule").Args["copy_commands"]
diff --git a/apex/builder.go b/apex/builder.go
index ad673d6..acfb8c5 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -373,14 +373,7 @@
 		panic(fmt.Errorf("error while marshalling to %q: %#v", output, err))
 	}
 
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Output:      output,
-		Description: "Bundle Config " + output.String(),
-		Args: map[string]string{
-			"content": string(j),
-		},
-	})
+	android.WriteFileRule(ctx, output, string(j))
 
 	return output.OutputPath
 }
diff --git a/apex/key.go b/apex/key.go
index d2d5786..43764da 100644
--- a/apex/key.go
+++ b/apex/key.go
@@ -116,7 +116,7 @@
 		partition             string
 	}
 	toString := func(e apexKeyEntry) string {
-		format := "name=%q public_key=%q private_key=%q container_certificate=%q container_private_key=%q partition=%q\\n"
+		format := "name=%q public_key=%q private_key=%q container_certificate=%q container_private_key=%q partition=%q\n"
 		if e.presigned {
 			return fmt.Sprintf(format, e.name, "PRESIGNED", "PRESIGNED", "PRESIGNED", "PRESIGNED", e.partition)
 		} else {
@@ -173,17 +173,9 @@
 
 	var filecontent strings.Builder
 	for _, name := range moduleNames {
-		fmt.Fprintf(&filecontent, "%s", toString(apexKeyMap[name]))
+		filecontent.WriteString(toString(apexKeyMap[name]))
 	}
-
-	ctx.Build(pctx, android.BuildParams{
-		Rule:        android.WriteFile,
-		Description: "apexkeys.txt",
-		Output:      s.output,
-		Args: map[string]string{
-			"content": filecontent.String(),
-		},
-	})
+	android.WriteFileRule(ctx, s.output, filecontent.String())
 }
 
 func apexKeysTextFactory() android.Singleton {