diff --git a/src/arch/riscv/regs/float.hh b/src/arch/riscv/regs/float.hh
index 1654bdb627..4809372070 100644
--- a/src/arch/riscv/regs/float.hh
+++ b/src/arch/riscv/regs/float.hh
@@ -105,7 +105,7 @@ static constexpr float64_t f64(freg_t r) { return r; }
 static constexpr freg_t freg(float16_t f) { return {boxF16(f.v)}; }
 static constexpr freg_t freg(float32_t f) { return {boxF32(f.v)}; }
 static constexpr freg_t freg(float64_t f) { return f; }
-static constexpr freg_t freg(uint_fast16_t f) { return {f}; }
+static constexpr freg_t freg(uint_fast64_t f) { return {f}; }
 
 namespace float_reg
 {