diff --git a/src/simulator/machine.rs b/src/simulator/machine.rs
index 4d4ee63..1981c8e 100644
--- a/src/simulator/machine.rs
+++ b/src/simulator/machine.rs
@@ -470,20 +470,20 @@ impl Machine {
 						machine.fp_reg.set_reg(inst.rd as usize, machine.fp_reg.get_reg(inst.rs1 as usize).sqrt());
 					},
 					RISCV_FP_FSGN => {
-						let local_float = machine.fp_reg[inst.rs1 as usize];
+						let local_float = machine.fp_reg.get_reg(inst.rs1 as usize);
 						match inst.funct3 {
 							RISCV_FP_FSGN_J => {
-								if machine.fp_reg[inst.rs2 as usize] < 0 {
-									machine.fp_reg[inst.rd as usize] = -local_float;
+								if machine.fp_reg.get_reg(inst.rs2 as usize) < 0f32 {
+									machine.fp_reg.set_reg(inst.rd as usize, -local_float);
 								} else {
-									machine.fp_reg[inst.rd as usize] = local_float;
+									machine.fp_reg.set_reg(inst.rd as usize, local_float);
 								}
 							}
 							RISCV_FP_FSGN_JN => {
-								if machine.fp_reg[inst.rs2 as usize] < 0 {
-									machine.fp_reg[inst.rd as usize] = local_float;
+								if machine.fp_reg.get_reg(inst.rs2 as usize) < 0f32 {
+									machine.fp_reg.set_reg(inst.rd as usize, local_float);
 								} else {
-									machine.fp_reg[inst.rd as usize] = -local_float;
+									machine.fp_reg.set_reg(inst.rd as usize, -local_float);
 								}
 							}
 							RISCV_FP_FSGN_JX => {