diff --git a/src/simulator/print.rs b/src/simulator/print.rs
index a76fbd6..e6d5a54 100644
--- a/src/simulator/print.rs
+++ b/src/simulator/print.rs
@@ -68,13 +68,13 @@ pub fn print(ins: Instruction, pc: i32) -> String { //TODO pc should be u64
             }
         },
         RISCV_LUI => {
-            format!("lui\t{}, 0x{:X}", REG_X[rd], ins.imm31_12)
+            format!("lui\t{}, 0x{:x}", REG_X[rd], ins.imm31_12)
         },
         RISCV_AUIPC => {
-            format!("auipc\t{}, {:X}", REG_X[rd], ins.imm31_12)
+            format!("auipc\t{}, {:x}", REG_X[rd], ins.imm31_12)
         },
         RISCV_JAL => {
-            format!("jal\t{},{:X}", REG_X[rd], (pc + ins.imm21_1_signed)) 
+            format!("jal\t{},{:x}", REG_X[rd], (pc + ins.imm21_1_signed)) 
         },
         RISCV_JALR => {
             format!("jalr\t{},{}({})", REG_X[rd], ins.imm12_I_signed, REG_X[rs1])
@@ -174,8 +174,8 @@ mod test {
     fn test_lui() {
         let lui = decode::decode(0b01110001000011111000_11100_0110111);
         let lui_negatif = decode::decode(0b11110001000011111000_11100_0110111);
-        assert_eq!("lui\tt3, 0x710F8000", print::print(lui, 0));
-        assert_eq!("lui\tt3, 0xF10F8000", print::print(lui_negatif, 0));
+        assert_eq!("lui\tt3, 0x710f8000", print::print(lui, 0));
+        assert_eq!("lui\tt3, 0xf10f8000", print::print(lui_negatif, 0));
     }
 
     #[test]