diff --git a/src/Reactor/reactor.gni b/src/Reactor/reactor.gni
index f8de370..04fad6f 100644
--- a/src/Reactor/reactor.gni
+++ b/src/Reactor/reactor.gni
@@ -9,8 +9,8 @@
 import("//build_overrides/build.gni")
 
 declare_args() {
-  # Subzero doesn't support ARM64, MIPS64, and PPC64 (only x86 and ARMv7a).
-  supports_subzero = current_cpu != "arm64" && current_cpu != "mips64el" && current_cpu != "ppc64"
+  # Subzero doesn't support ARM64, MIPS64, PPC64, and RISCV64 (only x86 and ARMv7a).
+  supports_subzero = current_cpu != "arm64" && current_cpu != "mips64el" && current_cpu != "ppc64" && current_cpu != "riscv64"
 }
 
 declare_args() {
@@ -25,4 +25,4 @@
   # Subzero produces much smaller binaries, so always use it when available,
   # except for MSan builds which only get Reactor code instrumented with LLVM.
   use_swiftshader_with_subzero = supports_subzero && !is_msan
-}
\ No newline at end of file
+}