diff --git a/apex/apex_test.go b/apex/apex_test.go
index 5d7a1be..4a5373f 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -8289,6 +8289,75 @@
 	`)
 }
 
+func TestAndroidMk_DexpreoptBuiltInstalledForApex(t *testing.T) {
+	ctx := testApex(t, `
+		apex {
+			name: "myapex",
+			key: "myapex.key",
+			updatable: false,
+			java_libs: ["foo"],
+		}
+
+		apex_key {
+			name: "myapex.key",
+			public_key: "testkey.avbpubkey",
+			private_key: "testkey.pem",
+		}
+
+		java_library {
+			name: "foo",
+			srcs: ["foo.java"],
+			apex_available: ["myapex"],
+			installable: true,
+		}
+	`,
+		dexpreopt.FixtureSetApexSystemServerJars("myapex:foo"),
+	)
+
+	apexBundle := ctx.ModuleForTests("myapex", "android_common_myapex_image").Module().(*apexBundle)
+	data := android.AndroidMkDataForTest(t, ctx, apexBundle)
+	var builder strings.Builder
+	data.Custom(&builder, apexBundle.BaseModuleName(), "TARGET_", "", data)
+	androidMk := builder.String()
+	ensureContains(t, androidMk, "LOCAL_REQUIRED_MODULES += foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.odex foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.vdex")
+}
+
+func TestAndroidMk_DexpreoptBuiltInstalledForApex_Prebuilt(t *testing.T) {
+	ctx := testApex(t, `
+		prebuilt_apex {
+			name: "myapex",
+			arch: {
+				arm64: {
+					src: "myapex-arm64.apex",
+				},
+				arm: {
+					src: "myapex-arm.apex",
+				},
+			},
+			exported_java_libs: ["foo"],
+		}
+
+		java_import {
+			name: "foo",
+			jars: ["foo.jar"],
+			installable: true,
+		}
+	`,
+		dexpreopt.FixtureSetApexSystemServerJars("myapex:foo"),
+	)
+
+	prebuilt := ctx.ModuleForTests("myapex", "android_common_myapex").Module().(*Prebuilt)
+	entriesList := android.AndroidMkEntriesForTest(t, ctx, prebuilt)
+	mainModuleEntries := entriesList[0]
+	android.AssertArrayString(t,
+		"LOCAL_REQUIRED_MODULES",
+		mainModuleEntries.EntryMap["LOCAL_REQUIRED_MODULES"],
+		[]string{
+			"foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.odex",
+			"foo-dexpreopt-arm64-apex@myapex@javalib@foo.jar@classes.vdex",
+		})
+}
+
 func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
diff --git a/cc/config/global.go b/cc/config/global.go
index 5f41f9e..ba10491 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -77,10 +77,6 @@
 		// TODO: can we remove this now?
 		"-Wno-reserved-id-macro",
 
-		// Workaround for ccache with clang.
-		// See http://petereisentraut.blogspot.com/2011/05/ccache-and-clang.html.
-		"-Wno-unused-command-line-argument",
-
 		// Force clang to always output color diagnostics. Ninja will strip the ANSI
 		// color codes if it is not running in a terminal.
 		"-fcolor-diagnostics",
@@ -329,6 +325,12 @@
 			// Default to zero initialization.
 			flags = append(flags, "-ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang")
 		}
+
+		// Workaround for ccache with clang.
+		// See http://petereisentraut.blogspot.com/2011/05/ccache-and-clang.html.
+		if ctx.Config().IsEnvTrue("USE_CCACHE") {
+			flags = append(flags, "-Wno-unused-command-line-argument")
+		}
 		return strings.Join(flags, " ")
 	})
 
diff --git a/scripts/get_clang_version.py b/scripts/get_clang_version.py
index 64d922a..691c45d 100755
--- a/scripts/get_clang_version.py
+++ b/scripts/get_clang_version.py
@@ -34,7 +34,7 @@
   with open(global_go) as infile:
     contents = infile.read()
 
-  regex_rev = r'\tClangDefaultVersion\s+= "(?P<rev>clang-r\d+[a-z]?\d?)"'
+  regex_rev = r'\tClangDefaultVersion\s+= "(?P<rev>clang-.*)"'
   match_rev = re.search(regex_rev, contents)
   if match_rev is None:
     raise RuntimeError('Parsing clang info failed')