diff --git a/cc/config/clang.go b/cc/config/clang.go
index 8618d0955..eddc34104 100644
--- a/cc/config/clang.go
+++ b/cc/config/clang.go
@@ -132,10 +132,6 @@ func init() {
 		// Disable -Winconsistent-missing-override until we can clean up the existing
 		// codebase for it.
 		"-Wno-inconsistent-missing-override",
-
-		// Warnings from clang-10
-		// Nested and array designated initialization is nice to have.
-		"-Wno-c99-designator",
 	}, " "))
 
 	pctx.StaticVariable("ClangExtraCppflags", strings.Join([]string{
@@ -165,10 +161,6 @@ func init() {
 		// new warnings are fixed.
 		"-Wno-tautological-constant-compare",
 		"-Wno-tautological-type-limit-compare",
-		// http://b/145210666
-		"-Wno-reorder-init-list",
-		// http://b/145211066
-		"-Wno-implicit-int-float-conversion",
 	}, " "))
 
 	// Extra cflags for external third-party projects to disable warnings that
@@ -184,13 +176,6 @@ func init() {
 		// Bug: http://b/29823425 Disable -Wnull-dereference until the
 		// new instances detected by this warning are fixed.
 		"-Wno-null-dereference",
-
-		// http://b/145211477
-		"-Wno-pointer-compare",
-		// http://b/145211022
-		"-Wno-xor-used-as-pow",
-		// http://b/145211022
-		"-Wno-final-dtor-non-final-class",
 	}, " "))
 }
 
diff --git a/cc/config/global.go b/cc/config/global.go
index bae5555f9..0a09fa4e7 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -126,8 +126,8 @@ var (
 
 	// prebuilts/clang default settings.
 	ClangDefaultBase         = "prebuilts/clang/host"
-	ClangDefaultVersion      = "clang-r370808"
-	ClangDefaultShortVersion = "10.0.1"
+	ClangDefaultVersion      = "clang-r365631b"
+	ClangDefaultShortVersion = "9.0.7"
 
 	// Directories with warnings from Android.bp files.
 	WarningAllowedProjects = []string{
diff --git a/cc/ndk_library.go b/cc/ndk_library.go
index da94d331c..c47cbf077 100644
--- a/cc/ndk_library.go
+++ b/cc/ndk_library.go
@@ -261,7 +261,6 @@ func addStubLibraryCompilerFlags(flags Flags) Flags {
 		// We're knowingly doing some otherwise unsightly things with builtin
 		// functions here. We're just generating stub libraries, so ignore it.
 		"-Wno-incompatible-library-redeclaration",
-		"-Wno-incomplete-setjmp-declaration",
 		"-Wno-builtin-requires-header",
 		"-Wno-invalid-noreturn",
 		"-Wall",