diff --git a/apex/apex.go b/apex/apex.go
index 58cbb13..ced8a6c 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -16,7 +16,6 @@
 
 import (
 	"fmt"
-	"path"
 	"path/filepath"
 	"sort"
 	"strings"
@@ -1242,7 +1241,7 @@
 	container_certificate_file android.Path
 	container_private_key_file android.Path
 
-	fileContexts android.Path
+	fileContexts android.WritablePath
 
 	// list of files to be included in this apex
 	filesInfo []apexFile
@@ -2174,22 +2173,6 @@
 	a.installDir = android.PathForModuleInstall(ctx, "apex")
 	a.filesInfo = filesInfo
 
-	if a.properties.ApexType != zipApex {
-		if a.properties.File_contexts == nil {
-			a.fileContexts = android.PathForSource(ctx, "system/sepolicy/apex", ctx.ModuleName()+"-file_contexts")
-		} else {
-			a.fileContexts = android.PathForModuleSrc(ctx, *a.properties.File_contexts)
-			if a.Platform() {
-				if matched, err := path.Match("system/sepolicy/**/*", a.fileContexts.String()); err != nil || !matched {
-					ctx.PropertyErrorf("file_contexts", "should be under system/sepolicy, but %q", a.fileContexts)
-				}
-			}
-		}
-		if !android.ExistentPathForSource(ctx, a.fileContexts.String()).Valid() {
-			ctx.PropertyErrorf("file_contexts", "cannot find file_contexts file: %q", a.fileContexts)
-			return
-		}
-	}
 	// Optimization. If we are building bundled APEX, for the files that are gathered due to the
 	// transitive dependencies, don't place them inside the APEX, but place a symlink pointing
 	// the same library in the system partition, thus effectively sharing the same libraries
@@ -2213,6 +2196,8 @@
 	// prepare apex_manifest.json
 	a.buildManifest(ctx, provideNativeLibs, requireNativeLibs)
 
+	a.buildFileContexts(ctx)
+
 	a.setCertificateAndPrivateKey(ctx)
 	if a.properties.ApexType == flattenedApex {
 		a.buildFlattenedApex(ctx)
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 38c8489..910e53a 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3275,110 +3275,104 @@
 	}
 }
 
-func TestFileContexts(t *testing.T) {
+func TestFileContexts_FindInDefaultLocationIfNotSet(t *testing.T) {
 	ctx, _ := testApex(t, `
-	apex {
-		name: "myapex",
-		key: "myapex.key",
-	}
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+		}
 
-	apex_key {
-		name: "myapex.key",
-		public_key: "testkey.avbpubkey",
-		private_key: "testkey.pem",
-	}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
 	`)
 	module := ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	apexRule := module.Rule("apexRule")
-	actual := apexRule.Args["file_contexts"]
-	expected := "system/sepolicy/apex/myapex-file_contexts"
-	if actual != expected {
-		t.Errorf("wrong file_contexts. expected %q. actual %q", expected, actual)
-	}
+	rule := module.Output("file_contexts")
+	ensureContains(t, rule.RuleParams.Command, "cat system/sepolicy/apex/myapex-file_contexts")
+}
 
+func TestFileContexts_ShouldBeUnderSystemSepolicyForSystemApexes(t *testing.T) {
 	testApexError(t, `"myapex" .*: file_contexts: should be under system/sepolicy`, `
-	apex {
-		name: "myapex",
-		key: "myapex.key",
-		file_contexts: "my_own_file_contexts",
-	}
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			file_contexts: "my_own_file_contexts",
+		}
 
-	apex_key {
-		name: "myapex.key",
-		public_key: "testkey.avbpubkey",
-		private_key: "testkey.pem",
-	}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
 	`, withFiles(map[string][]byte{
 		"my_own_file_contexts": nil,
 	}))
+}
 
+func TestFileContexts_ProductSpecificApexes(t *testing.T) {
 	testApexError(t, `"myapex" .*: file_contexts: cannot find`, `
-	apex {
-		name: "myapex",
-		key: "myapex.key",
-		product_specific: true,
-		file_contexts: "product_specific_file_contexts",
-	}
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			product_specific: true,
+			file_contexts: "product_specific_file_contexts",
+		}
 
-	apex_key {
-		name: "myapex.key",
-		public_key: "testkey.avbpubkey",
-		private_key: "testkey.pem",
-	}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
 	`)
 
-	ctx, _ = testApex(t, `
-	apex {
-		name: "myapex",
-		key: "myapex.key",
-		product_specific: true,
-		file_contexts: "product_specific_file_contexts",
-	}
+	ctx, _ := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			product_specific: true,
+			file_contexts: "product_specific_file_contexts",
+		}
 
-	apex_key {
-		name: "myapex.key",
-		public_key: "testkey.avbpubkey",
-		private_key: "testkey.pem",
-	}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
 	`, withFiles(map[string][]byte{
 		"product_specific_file_contexts": nil,
 	}))
-	module = ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	apexRule = module.Rule("apexRule")
-	actual = apexRule.Args["file_contexts"]
-	expected = "product_specific_file_contexts"
-	if actual != expected {
-		t.Errorf("wrong file_contexts. expected %q. actual %q", expected, actual)
-	}
+	module := ctx.ModuleForTests("myapex", "android_common_myapex_image")
+	rule := module.Output("file_contexts")
+	ensureContains(t, rule.RuleParams.Command, "cat product_specific_file_contexts")
+}
 
-	ctx, _ = testApex(t, `
-	apex {
-		name: "myapex",
-		key: "myapex.key",
-		product_specific: true,
-		file_contexts: ":my-file-contexts",
-	}
+func TestFileContexts_SetViaFileGroup(t *testing.T) {
+	ctx, _ := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			product_specific: true,
+			file_contexts: ":my-file-contexts",
+		}
 
-	apex_key {
-		name: "myapex.key",
-		public_key: "testkey.avbpubkey",
-		private_key: "testkey.pem",
-	}
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
 
-	filegroup {
-		name: "my-file-contexts",
-		srcs: ["product_specific_file_contexts"],
-	}
+		filegroup {
+			name: "my-file-contexts",
+			srcs: ["product_specific_file_contexts"],
+		}
 	`, withFiles(map[string][]byte{
 		"product_specific_file_contexts": nil,
 	}))
-	module = ctx.ModuleForTests("myapex", "android_common_myapex_image")
-	apexRule = module.Rule("apexRule")
-	actual = apexRule.Args["file_contexts"]
-	expected = "product_specific_file_contexts"
-	if actual != expected {
-		t.Errorf("wrong file_contexts. expected %q. actual %q", expected, actual)
-	}
+	module := ctx.ModuleForTests("myapex", "android_common_myapex_image")
+	rule := module.Output("file_contexts")
+	ensureContains(t, rule.RuleParams.Command, "cat product_specific_file_contexts")
 }
 
 func TestApexKeyFromOtherModule(t *testing.T) {
diff --git a/apex/builder.go b/apex/builder.go
index af43417..ac3e640 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -17,6 +17,7 @@
 import (
 	"encoding/json"
 	"fmt"
+	"path"
 	"path/filepath"
 	"runtime"
 	"sort"
@@ -231,6 +232,38 @@
 	})
 }
 
+func (a *apexBundle) buildFileContexts(ctx android.ModuleContext) {
+	if a.properties.ApexType == zipApex {
+		return
+	}
+	var fileContexts android.Path
+	if a.properties.File_contexts == nil {
+		fileContexts = android.PathForSource(ctx, "system/sepolicy/apex", ctx.ModuleName()+"-file_contexts")
+	} else {
+		fileContexts = android.PathForModuleSrc(ctx, *a.properties.File_contexts)
+	}
+	if a.Platform() {
+		if matched, err := path.Match("system/sepolicy/**/*", fileContexts.String()); err != nil || !matched {
+			ctx.PropertyErrorf("file_contexts", "should be under system/sepolicy, but %q", fileContexts)
+			return
+		}
+	}
+	if !android.ExistentPathForSource(ctx, fileContexts.String()).Valid() {
+		ctx.PropertyErrorf("file_contexts", "cannot find file_contexts file: %q", a.fileContexts)
+		return
+	}
+
+	output := android.PathForModuleOut(ctx, "file_contexts")
+	rule := android.NewRuleBuilder()
+	rule.Command().Text("rm").FlagWithOutput("-f ", output)
+	rule.Command().Text("cat").Input(fileContexts).Text(">>").Output(output)
+	rule.Command().Text("echo").Text(">>").Output(output)
+	rule.Command().Text("echo").Flag("/apex_manifest\\\\.pb u:object_r:system_file:s0").Text(">>").Output(output)
+	rule.Build(pctx, ctx, "file_contexts."+a.Name(), "Generate file_contexts")
+
+	a.fileContexts = output.OutputPath
+}
+
 func (a *apexBundle) buildNoticeFiles(ctx android.ModuleContext, apexFileName string) android.NoticeOutputs {
 	var noticeFiles android.Paths