--- a/vendor/compiler_builtins-0.1.133/configure.rs
+++ b/vendor/compiler_builtins-0.1.133/configure.rs
@@ -72,6 +72,8 @@ pub fn configure_f16_f128(target: &Target) {
         "sparc" | "sparcv9" => (true, false),
         // `f16` miscompiles <https://github.com/llvm/llvm-project/issues/96438>
         "wasm32" | "wasm64" => (false, true),
+        "loongarch64" => (false, true),
+        "riscv64" | "riscv64gc" => (false, true),
         // Most everything else works as of LLVM 19
         _ => (true, true),
     };