diff --git a/android/androidmk.go b/android/androidmk.go
index 6197f59..d5ee045 100644
--- a/android/androidmk.go
+++ b/android/androidmk.go
@@ -45,9 +45,11 @@
 
 	Custom func(w io.Writer, name, prefix, moduleDir string) error
 
-	Extra []func(w io.Writer, outputFile Path) error
+	Extra []AndroidMkExtraFunc
 }
 
+type AndroidMkExtraFunc func(w io.Writer, outputFile Path)
+
 func AndroidMkSingleton() blueprint.Singleton {
 	return &androidMkSingleton{}
 }
@@ -255,10 +257,7 @@
 	}
 
 	for _, extra := range data.Extra {
-		err = extra(w, data.OutputFile.Path())
-		if err != nil {
-			return err
-		}
+		extra(w, data.OutputFile.Path())
 	}
 
 	fmt.Fprintln(w, "include $(BUILD_PREBUILT)")
diff --git a/cc/androidmk.go b/cc/androidmk.go
index 940e7c7..f68ddbb 100644
--- a/cc/androidmk.go
+++ b/cc/androidmk.go
@@ -56,7 +56,7 @@
 	}
 
 	ret.OutputFile = c.outputFile
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) (err error) {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_SANITIZE := never")
 		if len(c.Properties.AndroidMkSharedLibs) > 0 {
 			fmt.Fprintln(w, "LOCAL_SHARED_LIBRARIES := "+strings.Join(c.Properties.AndroidMkSharedLibs, " "))
@@ -71,7 +71,6 @@
 		if c.vndk() {
 			fmt.Fprintln(w, "LOCAL_USE_VNDK := true")
 		}
-		return nil
 	})
 
 	for _, feature := range c.features {
@@ -106,9 +105,8 @@
 		testFiles = append(testFiles, path+":"+rel)
 	}
 	if len(testFiles) > 0 {
-		ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+		ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 			fmt.Fprintln(w, "LOCAL_TEST_DATA := "+strings.Join(testFiles, " "))
-			return nil
 		})
 	}
 }
@@ -167,7 +165,7 @@
 		return
 	}
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		library.androidMkWriteExportedFlags(w)
 		fmt.Fprintln(w, "LOCAL_ADDITIONAL_DEPENDENCIES := ")
 		if library.sAbiOutputFile.Valid() {
@@ -185,8 +183,6 @@
 		if library.coverageOutputFile.Valid() {
 			fmt.Fprintln(w, "LOCAL_PREBUILT_COVERAGE_ARCHIVE :=", library.coverageOutputFile.String())
 		}
-
-		return nil
 	})
 
 	if library.shared() {
@@ -210,7 +206,7 @@
 	ctx.subAndroidMk(ret, &binary.stripper)
 
 	ret.Class = "EXECUTABLES"
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_SYSTEM_SHARED_LIBRARIES :=")
 		if Bool(binary.Properties.Static_executable) {
 			fmt.Fprintln(w, "LOCAL_FORCE_STATIC_EXECUTABLE := true")
@@ -223,19 +219,17 @@
 		if binary.coverageOutputFile.Valid() {
 			fmt.Fprintln(w, "LOCAL_PREBUILT_COVERAGE_ARCHIVE :=", binary.coverageOutputFile.String())
 		}
-		return nil
 	})
 }
 
 func (benchmark *benchmarkDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
 	ctx.subAndroidMk(ret, benchmark.binaryDecorator)
 	ret.Class = "NATIVE_TESTS"
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		if len(benchmark.Properties.Test_suites) > 0 {
 			fmt.Fprintln(w, "LOCAL_COMPATIBILITY_SUITE :=",
 				strings.Join(benchmark.Properties.Test_suites, " "))
 		}
-		return nil
 	})
 
 	androidMkWriteTestData(benchmark.data, ctx, ret)
@@ -248,12 +242,11 @@
 		ret.SubName = "_" + test.binaryDecorator.Properties.Stem
 	}
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		if len(test.Properties.Test_suites) > 0 {
 			fmt.Fprintln(w, "LOCAL_COMPATIBILITY_SUITE :=",
 				strings.Join(test.Properties.Test_suites, " "))
 		}
-		return nil
 	})
 
 	androidMkWriteTestData(test.data, ctx, ret)
@@ -265,11 +258,9 @@
 
 func (library *toolchainLibraryDecorator) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
 	ret.Class = "STATIC_LIBRARIES"
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := "+outputFile.Ext())
 		fmt.Fprintln(w, "LOCAL_SYSTEM_SHARED_LIBRARIES :=")
-
-		return nil
 	})
 }
 
@@ -279,7 +270,7 @@
 		return
 	}
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		if stripper.StripProperties.Strip.None {
 			fmt.Fprintln(w, "LOCAL_STRIP_MODULE := false")
 		} else if stripper.StripProperties.Strip.Keep_symbols {
@@ -287,17 +278,14 @@
 		} else {
 			fmt.Fprintln(w, "LOCAL_STRIP_MODULE := mini-debug-info")
 		}
-
-		return nil
 	})
 }
 
 func (packer *relocationPacker) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		if packer.Properties.PackingRelocations {
 			fmt.Fprintln(w, "LOCAL_PACK_MODULE_RELOCATIONS := true")
 		}
-		return nil
 	})
 }
 
@@ -308,14 +296,13 @@
 		ret.OutputFile = android.OptionalPathForPath(installer.path)
 	}
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		path := installer.path.RelPathString()
 		dir, file := filepath.Split(path)
 		stem := strings.TrimSuffix(file, filepath.Ext(file))
 		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := "+filepath.Ext(file))
 		fmt.Fprintln(w, "LOCAL_MODULE_PATH := $(OUT_DIR)/"+filepath.Clean(dir))
 		fmt.Fprintln(w, "LOCAL_MODULE_STEM := "+stem)
-		return nil
 	})
 }
 
@@ -323,7 +310,7 @@
 	ret.SubName = ndkLibrarySuffix + "." + c.properties.ApiLevel
 	ret.Class = "SHARED_LIBRARIES"
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		path, file := filepath.Split(c.installPath)
 		stem := strings.TrimSuffix(file, filepath.Ext(file))
 		fmt.Fprintln(w, "LOCAL_SYSTEM_SHARED_LIBRARIES :=")
@@ -336,7 +323,6 @@
 		// dozens of libraries with the same name, they'll clobber each other
 		// and the real versions of the libraries from the platform).
 		fmt.Fprintln(w, "LOCAL_COPY_TO_INTERMEDIATE_LIBRARIES := false")
-		return nil
 	})
 }
 
@@ -344,7 +330,7 @@
 	ret.Class = "SHARED_LIBRARIES"
 	ret.SubName = ".vendor"
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		c.libraryDecorator.androidMkWriteExportedFlags(w)
 
 		fmt.Fprintln(w, "LOCAL_BUILT_MODULE_STEM := $(LOCAL_MODULE)"+outputFile.Ext())
@@ -353,7 +339,5 @@
 		fmt.Fprintln(w, "LOCAL_UNINSTALLABLE_MODULE := true")
 		fmt.Fprintln(w, "LOCAL_NO_NOTICE_FILE := true")
 		fmt.Fprintln(w, "LOCAL_USE_VNDK := true")
-
-		return nil
 	})
 }
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 1fcb32c..4ea4d26 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -444,12 +444,10 @@
 }
 
 func (sanitize *sanitize) AndroidMk(ctx AndroidMkContext, ret *android.AndroidMkData) {
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		if sanitize.androidMkRuntimeLibrary != "" {
 			fmt.Fprintln(w, "LOCAL_SHARED_LIBRARIES += "+sanitize.androidMkRuntimeLibrary)
 		}
-
-		return nil
 	})
 }
 
diff --git a/java/androidmk.go b/java/androidmk.go
index 92af0ed..fd967cb 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -24,9 +24,8 @@
 func (library *Library) AndroidMk() (ret android.AndroidMkData, err error) {
 	ret.Class = "JAVA_LIBRARIES"
 	ret.OutputFile = android.OptionalPathForPath(library.outputFile)
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := .jar")
-		return nil
 	})
 	return
 }
@@ -34,9 +33,8 @@
 func (prebuilt *Import) AndroidMk() (ret android.AndroidMkData, err error) {
 	ret.Class = "JAVA_LIBRARIES"
 	ret.OutputFile = android.OptionalPathForPath(prebuilt.combinedClasspathFile)
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := .jar")
-		return nil
 	})
 	return
 }
diff --git a/python/androidmk.go b/python/androidmk.go
index 0a79e73..386eeee 100644
--- a/python/androidmk.go
+++ b/python/androidmk.go
@@ -61,7 +61,7 @@
 		ret.OutputFile = android.OptionalPathForPath(installer.path)
 	}
 
-	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) {
 		path := installer.path.RelPathString()
 		dir, file := filepath.Split(path)
 		stem := strings.TrimSuffix(file, filepath.Ext(file))
@@ -69,6 +69,5 @@
 		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := "+filepath.Ext(file))
 		fmt.Fprintln(w, "LOCAL_MODULE_PATH := $(OUT_DIR)/"+filepath.Clean(dir))
 		fmt.Fprintln(w, "LOCAL_MODULE_STEM := "+stem)
-		return nil
 	})
 }