diff --git a/build/Android.bp b/build/Android.bp
index 24b4a93..5fe0892 100644
--- a/build/Android.bp
+++ b/build/Android.bp
@@ -40,6 +40,7 @@
         "aidl_api.go",
         "aidl_gen_rule.go",
         "aidl_interface_backends.go",
+        "aidl_interface_headers.go",
         "aidl_interface_metadata_singleton.go",
         "aidl_mapping.go",
         "aidl_rust_source_provider.go",
diff --git a/build/aidl_api.go b/build/aidl_api.go
index 1fc4474..fe821a6 100644
--- a/build/aidl_api.go
+++ b/build/aidl_api.go
@@ -55,6 +55,7 @@
 	AidlRoot  string   // base directory for the input aidl file
 	Stability *string
 	Imports   []string
+	Headers   []string
 	Versions  []string
 	Dumpapi   DumpApiProperties
 }
@@ -340,6 +341,14 @@
 			// add imported module's checkapiTimestamps as implicits to make sure that imported apiDump is up-to-date
 			deps.implicits = append(deps.implicits, api.checkApiTimestamps.Paths()...)
 			deps.implicits = append(deps.implicits, api.checkHashTimestamps.Paths()...)
+		case interfaceHeadersDepTag:
+			headerInfo, ok := ctx.OtherModuleProvider(dep, AidlInterfaceHeadersProvider).(AidlInterfaceHeadersInfo)
+			if !ok {
+				ctx.PropertyErrorf("headers", "module %v does not provide AidlInterfaceHeadersInfo", dep.Name())
+				return
+			}
+			deps.implicits = append(deps.implicits, headerInfo.Srcs...)
+			deps.imports = append(deps.imports, headerInfo.IncludeDir)
 		}
 	})
 	return deps
@@ -578,6 +587,7 @@
 		AidlRoot:  aidlRoot,
 		Stability: i.properties.Stability,
 		Imports:   i.properties.Imports,
+		Headers:   i.properties.Headers,
 		Versions:  i.getVersions(),
 		Dumpapi:   i.properties.Dumpapi,
 	})
diff --git a/build/aidl_gen_rule.go b/build/aidl_gen_rule.go
index 3dd0fde..6a326d1 100644
--- a/build/aidl_gen_rule.go
+++ b/build/aidl_gen_rule.go
@@ -66,6 +66,7 @@
 	Srcs            []string `android:"path"`
 	AidlRoot        string   // base directory for the input aidl file
 	Imports         []string
+	Headers         []string
 	Stability       *string
 	Min_sdk_version *string
 	Platform_apis   bool
@@ -114,12 +115,12 @@
 func (g *aidlGenRule) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	srcs, imports := getPaths(ctx, g.properties.Srcs, g.properties.AidlRoot)
 
+	g.deps = getDeps(ctx, g.getImports(ctx))
+
 	if ctx.Failed() {
 		return
 	}
 
-	g.deps = getDeps(ctx, g.getImports(ctx))
-
 	genDirTimestamp := android.PathForModuleGen(ctx, "timestamp") // $out/gen/timestamp
 	g.implicitInputs = append(g.implicitInputs, genDirTimestamp)
 	g.implicitInputs = append(g.implicitInputs, g.deps.implicits...)
diff --git a/build/aidl_interface.go b/build/aidl_interface.go
index 36527e4..e853c24 100644
--- a/build/aidl_interface.go
+++ b/build/aidl_interface.go
@@ -406,6 +406,10 @@
 
 	// --dumpapi options
 	Dumpapi DumpApiProperties
+
+	// List of aidl_interface_headers modules that provide include dependencies
+	// for the AIDL tool.
+	Headers []string
 }
 
 type aidlInterface struct {
@@ -490,6 +494,10 @@
 	blueprint.BaseDependencyTag
 }
 
+type interfaceHeadersDepTag struct {
+	blueprint.BaseDependencyTag
+}
+
 var (
 	// Dep from *-source (aidlGenRule) to *-api (aidlApi)
 	apiDep = apiDepTag{name: "api"}
@@ -497,6 +505,8 @@
 	importApiDep = apiDepTag{name: "imported-api"}
 	// Dep to original *-interface (aidlInterface)
 	interfaceDep = interfaceDepTag{}
+	// Dep for a header interface
+	interfaceHeadersDep = interfaceHeadersDepTag{}
 )
 
 func addImportedInterfaceDeps(ctx android.BottomUpMutatorContext, imports []string) {
@@ -529,6 +539,10 @@
 			return
 		}
 		addImportedInterfaceDeps(mctx, i.properties.Imports)
+
+		for _, header := range i.properties.Headers {
+			mctx.AddDependency(i, interfaceHeadersDep, header)
+		}
 	case *aidlImplementationGenerator:
 		mctx.AddDependency(i, interfaceDep, i.properties.AidlInterfaceName+aidlInterfaceSuffix)
 		addImportedInterfaceDeps(mctx, i.properties.Imports)
@@ -547,6 +561,9 @@
 			name, _ := parseModuleWithVersion(anImport)
 			mctx.AddDependency(i, importApiDep, name+aidlApiSuffix)
 		}
+		for _, header := range i.properties.Headers {
+			mctx.AddDependency(i, interfaceHeadersDep, header)
+		}
 	case *aidlGenRule:
 		mctx.AddDependency(i, interfaceDep, i.properties.BaseName+aidlInterfaceSuffix)
 		addImportedInterfaceDeps(mctx, i.properties.Imports)
@@ -554,6 +571,9 @@
 			// for checkapi timestamps
 			mctx.AddDependency(i, apiDep, i.properties.BaseName+aidlApiSuffix)
 		}
+		for _, header := range i.properties.Headers {
+			mctx.AddDependency(i, interfaceHeadersDep, header)
+		}
 	}
 }
 
@@ -936,6 +956,8 @@
 	}
 
 	paths, imports := getPaths(ctx, srcs, root_dir)
+	imports = append(imports, deps.imports...)
+	imports = append(imports, i.properties.Include_dirs...)
 
 	preprocessCommand := rb.Command().BuiltTool("aidl").
 		FlagWithOutput("--preprocess ", preprocessed).
@@ -944,7 +966,7 @@
 		preprocessCommand.FlagWithArg("--stability ", *i.properties.Stability)
 	}
 	preprocessCommand.FlagForEachInput("-p", deps.preprocessed)
-	preprocessCommand.FlagForEachArg("-I", concat(imports, i.properties.Include_dirs))
+	preprocessCommand.FlagForEachArg("-I", imports)
 	preprocessCommand.Inputs(paths)
 	name := i.BaseModuleName()
 	if version != "" {
diff --git a/build/aidl_interface_backends.go b/build/aidl_interface_backends.go
index 62a167c..54948ce 100644
--- a/build/aidl_interface_backends.go
+++ b/build/aidl_interface_backends.go
@@ -76,6 +76,7 @@
 		Srcs:            srcs,
 		AidlRoot:        aidlRoot,
 		Imports:         i.getImportsForVersion(version),
+		Headers:         i.properties.Headers,
 		Stability:       i.properties.Stability,
 		Min_sdk_version: i.minSdkVersion(lang),
 		Lang:            lang,
@@ -224,6 +225,7 @@
 		Srcs:            srcs,
 		AidlRoot:        aidlRoot,
 		Imports:         i.getImportsForVersion(version),
+		Headers:         i.properties.Headers,
 		Stability:       i.properties.Stability,
 		Min_sdk_version: minSdkVersion,
 		Platform_apis:   proptools.Bool(i.properties.Backend.Java.Platform_apis),
@@ -276,6 +278,7 @@
 		Srcs:            srcs,
 		AidlRoot:        aidlRoot,
 		Imports:         i.getImportsForVersion(version),
+		Headers:         i.properties.Headers,
 		Stability:       i.properties.Stability,
 		Min_sdk_version: i.minSdkVersion(langRust),
 		Lang:            langRust,
diff --git a/build/aidl_interface_headers.go b/build/aidl_interface_headers.go
new file mode 100644
index 0000000..0d59c4d
--- /dev/null
+++ b/build/aidl_interface_headers.go
@@ -0,0 +1,69 @@
+// Copyright (C) 2022 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package aidl
+
+import (
+	"path/filepath"
+
+	"android/soong/android"
+
+	"github.com/google/blueprint"
+	"github.com/google/blueprint/proptools"
+)
+
+func init() {
+	android.RegisterModuleType("aidl_interface_headers", aidlInterfaceHeadersFactory)
+}
+
+type AidlInterfaceHeadersInfo struct {
+	Srcs       android.Paths
+	IncludeDir string
+}
+
+var AidlInterfaceHeadersProvider = blueprint.NewProvider(AidlInterfaceHeadersInfo{})
+
+type aidlInterfaceHeadersProperties struct {
+	// List of .aidl files which compose this interface.
+	Srcs []string `android:"path"`
+
+	// Relative path for includes. assumes AIDL path is relative to current directory.
+	Include_dir *string
+}
+
+type aidlInterfaceHeaders struct {
+	android.ModuleBase
+
+	properties aidlInterfaceHeadersProperties
+
+	srcs android.Paths
+}
+
+// Modules which provide AIDL sources that are only used to provide "-I" flags to the
+// aidl tool. No language bindings are generated from these modules. Typically this will
+// be used to provide includes for UnstructuredParcelable AIDL definitions such as those
+// coming from framework modules.
+func aidlInterfaceHeadersFactory() android.Module {
+	i := &aidlInterfaceHeaders{}
+	i.AddProperties(&i.properties)
+	android.InitAndroidModule(i)
+	return i
+}
+
+func (i *aidlInterfaceHeaders) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	ctx.SetProvider(AidlInterfaceHeadersProvider, AidlInterfaceHeadersInfo{
+		Srcs:       android.PathsForModuleSrc(ctx, i.properties.Srcs),
+		IncludeDir: filepath.Join(ctx.ModuleDir(), proptools.String(i.properties.Include_dir)),
+	})
+}
diff --git a/build/aidl_test.go b/build/aidl_test.go
index 8c258db..11f8dd9 100644
--- a/build/aidl_test.go
+++ b/build/aidl_test.go
@@ -175,6 +175,7 @@
 		android.FixtureRegisterWithContext(func(ctx android.RegistrationContext) {
 			ctx.RegisterModuleType("aidl_interface", aidlInterfaceFactory)
 			ctx.RegisterModuleType("aidl_interfaces_metadata", aidlInterfacesMetadataSingletonFactory)
+			ctx.RegisterModuleType("aidl_interface_headers", aidlInterfaceHeadersFactory)
 			ctx.RegisterModuleType("rust_defaults", func() android.Module {
 				return rust.DefaultsFactory()
 			})
@@ -1097,6 +1098,7 @@
 				srcs: ["a/Foo.aidl"],
 				imports: ["bar-iface-V2"],
 				versions: ["1"],
+				headers: ["boq-iface-headers"],
 			}
 		`),
 		"foo/a/Foo.aidl": nil,
@@ -1129,13 +1131,21 @@
 		"baz/aidl_api/baz-iface/current/b/Baz.aidl": nil,
 		"baz/aidl_api/baz-iface/1/b/Baz.aidl":       nil,
 		"baz/aidl_api/baz-iface/1/.hash":            nil,
+
+		"boq/Android.bp": []byte(`
+			aidl_interface_headers {
+				name: "boq-iface-headers",
+				srcs: ["b/Boq.aidl"],
+			}
+		`),
+		"boq/b/Baz.aidl": nil,
 	})
 	ctx, _ := testAidl(t, ``, customizer)
 
 	// checkapidump rule is to compare "compatibility" between ToT(dump) and "current"
 	{
 		rule := ctx.ModuleForTests("foo-iface-api", "").Output("checkapi_dump.timestamp")
-		android.AssertStringEquals(t, "checkapi(dump == current) imports", "", rule.Args["imports"])
+		android.AssertStringEquals(t, "checkapi(dump == current) imports", "-Iboq", rule.Args["imports"])
 		android.AssertStringDoesContain(t, "checkapi(dump == current) optionalFlags",
 			rule.Args["optionalFlags"],
 			"-pout/soong/.intermediates/bar/bar-iface_interface/2/preprocessed.aidl")
@@ -1153,7 +1163,9 @@
 	// compile (v1)
 	{
 		rule := ctx.ModuleForTests("foo-iface-V1-cpp-source", "").Output("a/Foo.cpp")
-		android.AssertStringEquals(t, "compile(old=1) should import aidl_api/1", "-Ifoo/aidl_api/foo-iface/1", rule.Args["imports"])
+		android.AssertStringEquals(t, "compile(old=1) should import aidl_api/1",
+			"-Ifoo/aidl_api/foo-iface/1 -Iboq",
+			rule.Args["imports"])
 		android.AssertStringDoesContain(t, "compile(old=1) should import bar.preprocessed",
 			rule.Args["optionalFlags"],
 			"-pout/soong/.intermediates/bar/bar-iface_interface/2/preprocessed.aidl")
@@ -1161,7 +1173,7 @@
 	// compile ToT(v2)
 	{
 		rule := ctx.ModuleForTests("foo-iface-V2-cpp-source", "").Output("a/Foo.cpp")
-		android.AssertStringEquals(t, "compile(tot=2) should import base dirs of srcs", "-Ifoo", rule.Args["imports"])
+		android.AssertStringEquals(t, "compile(tot=2) should import base dirs of srcs", "-Ifoo -Iboq", rule.Args["imports"])
 		android.AssertStringDoesContain(t, "compile(tot=2) should import bar.preprocessed",
 			rule.Args["optionalFlags"],
 			"-pout/soong/.intermediates/bar/bar-iface_interface/2/preprocessed.aidl")