diff --git a/sysdeps/riscv/math-use-builtins-ffs.h b/sysdeps/riscv/math-use-builtins-ffs.h
new file mode 100644
index 0000000000..8104e29f84
--- /dev/null
+++ b/sysdeps/riscv/math-use-builtins-ffs.h
@@ -0,0 +1,10 @@
+#if defined COMPILER_ZBB_AVAIL && defined __riscv_zbb
+#  define USE_FFS_BUILTIN 1
+#  define USE_FFSLL_BUILTIN 1
+#elif defined COMPILER_XTHEADBB_AVAIL && defined __riscv_xtheadbb
+#  define USE_FFS_BUILTIN 0
+#  define USE_FFSLL_BUILTIN 1
+#else
+#  define USE_FFS_BUILTIN 0
+#  define USE_FFSLL_BUILTIN 0
+#endif