diff --git a/cc/config/riscv64_device.go b/cc/config/riscv64_device.go
index 67208b2..194b242 100644
--- a/cc/config/riscv64_device.go
+++ b/cc/config/riscv64_device.go
@@ -26,12 +26,16 @@
 		// Help catch common 32/64-bit errors.
 		"-Werror=implicit-function-declaration",
 		"-fno-emulated-tls",
+		// For -fsanitize=shadow-call-stack.
+		"-ffixed-x18",
 	}
 
 	riscv64ArchVariantCflags = map[string][]string{}
 
 	riscv64Ldflags = []string{
 		"-Wl,--hash-style=gnu",
+		// For -fsanitize=shadow-call-stack.
+		"-ffixed-x18",
 	}
 
 	riscv64Lldflags = append(riscv64Ldflags,
diff --git a/cc/sanitize.go b/cc/sanitize.go
index 66f459a..a31a358 100644
--- a/cc/sanitize.go
+++ b/cc/sanitize.go
@@ -254,7 +254,7 @@
 	// This should not be used in Android 11+ : https://source.android.com/devices/tech/debug/scudo
 	// deprecated
 	Scudo *bool `android:"arch_variant"`
-	// shadow-call-stack sanitizer, only available on arm64
+	// shadow-call-stack sanitizer, only available on arm64/riscv64.
 	Scs *bool `android:"arch_variant"`
 	// Memory-tagging, only available on arm64
 	// if diag.memtag unset or false, enables async memory tagging
@@ -593,8 +593,8 @@
 		s.Hwaddress = nil
 	}
 
-	// SCS is only implemented on AArch64.
-	if ctx.Arch().ArchType != android.Arm64 || !ctx.toolchain().Bionic() {
+	// SCS is only implemented on AArch64/riscv64.
+	if (ctx.Arch().ArchType != android.Arm64 && ctx.Arch().ArchType != android.Riscv64) || !ctx.toolchain().Bionic() {
 		s.Scs = nil
 	}