diff --git a/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h b/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h
index 225e3fa72..37fde0323 100644
--- a/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h
+++ b/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h
@@ -137,6 +137,23 @@ static inline tokutime_t toku_time_now(void) {
   uint64_t result;
   asm volatile("stckf %0" : "=Q"(result) : : "cc");
   return result;
+#elif defined(__riscv) && __riscv_xlen == 32
+  uint32_t cycles_lo, cycles_hi0, cycles_hi1;
+  // Implemented in assembly because Clang insisted on branching.
+  asm volatile(
+      "rdcycleh %0\n"
+      "rdcycle %1\n"
+      "rdcycleh %2\n"
+      "sub %0, %0, %2\n"
+      "seqz %0, %0\n"
+      "sub %0, zero, %0\n"
+      "and %1, %1, %0\n"
+      : "=r"(cycles_hi0), "=r"(cycles_lo), "=r"(cycles_hi1));
+  return (static_cast<uint64_t>(cycles_hi1) << 32) | cycles_lo;
+#elif defined(__riscv) && __riscv_xlen == 64
+  uint64_t cycles;
+  asm volatile("rdcycle %0" : "=r"(cycles));
+  return cycles;
 #else
 #error No timer implementation for this platform
 #endif