diff --git a/common/src/instructions/tests.rs b/common/src/instructions/tests.rs
index dcda497..114e7da 100644
--- a/common/src/instructions/tests.rs
+++ b/common/src/instructions/tests.rs
@@ -196,8 +196,12 @@ fn test_instruction_decode_misc() {
 #[test]
 fn test_instruction_decode_invalid() {
     // Test with invalid opcode.
-    let invalid_encoded = 0xFF00_0000;
-    assert!(Instruction::decode(invalid_encoded).is_err());
+    let invalid_encoded = 0xF500_0000;
+    let decode = Instruction::decode(invalid_encoded);
+
+    dbg!(&decode);
+
+    assert!(decode.is_err());
 }
 
 // TODO: Get interrupts working.
diff --git a/emulator/src/emulator/system/processor/tests.rs b/emulator/src/emulator/system/processor/tests.rs
index 3a6eb74..5636a61 100644
--- a/emulator/src/emulator/system/processor/tests.rs
+++ b/emulator/src/emulator/system/processor/tests.rs
@@ -64,8 +64,11 @@ fn test_load_byte_instruction() {
     cpu.memory.write_byte(addr, 0xAB);
     *cpu.reg(Register::Rg1) = addr - 4;
 
-    let load_byte_instr =
-        Instruction::LoadByte(ITypeArgs::new(4, Some(Register::Rg1), Some(Register::Rg2)));
+    let load_byte_instr = Instruction::LoadByte(ITypeArgs::new(
+        4,
+        Some(Register::Rg1),
+        Some(Register::Rg2),
+    ));
 
     load_byte_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg2), 0x0000_00AB);
@@ -78,8 +81,11 @@ fn test_load_byte_signed_instruction() {
     cpu.memory.write_byte(addr, 0xFF);
     *cpu.reg(Register::Rg1) = addr;
 
-    let load_byte_signed_instr =
-        Instruction::LoadByteSigned(ITypeArgs::new(0, Some(Register::Rg1), Some(Register::Rg2)));
+    let load_byte_signed_instr = Instruction::LoadByteSigned(ITypeArgs::new(
+        0,
+        Some(Register::Rg1),
+        Some(Register::Rg2),
+    ));
 
     load_byte_signed_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg2), 0xFFFF_FFFF);
@@ -92,8 +98,11 @@ fn test_load_halfword_instruction() {
     cpu.memory.write_word(addr, 0x1234_5678);
     *cpu.reg(Register::Rg1) = addr;
 
-    let load_halfword_instr =
-        Instruction::LoadHalfword(ITypeArgs::new(0, Some(Register::Rg1), Some(Register::Rg2)));
+    let load_halfword_instr = Instruction::LoadHalfword(ITypeArgs::new(
+        0,
+        Some(Register::Rg1),
+        Some(Register::Rg2),
+    ));
 
     load_halfword_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg2), 0x0000_1234);
@@ -106,8 +115,11 @@ fn test_load_word_instruction() {
     cpu.memory.write_word(addr, 0x1234_5678);
     *cpu.reg(Register::Rg1) = addr;
 
-    let load_word_instr =
-        Instruction::LoadWord(ITypeArgs::new(0, Some(Register::Rg1), Some(Register::Rg2)));
+    let load_word_instr = Instruction::LoadWord(ITypeArgs::new(
+        0,
+        Some(Register::Rg1),
+        Some(Register::Rg2),
+    ));
 
     load_word_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg2), 0x1234_5678);
@@ -120,8 +132,11 @@ fn test_store_byte_instruction() {
     *cpu.reg(Register::Rg1) = addr;
     *cpu.reg(Register::Rg2) = 0xAB;
 
-    let store_byte_instr =
-        Instruction::StoreByte(ITypeArgs::new(0, Some(Register::Rg1), Some(Register::Rg2)));
+    let store_byte_instr = Instruction::StoreByte(ITypeArgs::new(
+        0,
+        Some(Register::Rg2),
+        Some(Register::Rg1),
+    ));
 
     store_byte_instr.execute(&mut cpu);
     assert_eq!(cpu.memory.read_byte(addr), 0xAB);
@@ -134,8 +149,11 @@ fn test_store_word_instruction() {
     *cpu.reg(Register::Rg1) = addr;
     *cpu.reg(Register::Rg2) = 0x1234_5678;
 
-    let store_word_instr =
-        Instruction::StoreWord(ITypeArgs::new(0, Some(Register::Rg1), Some(Register::Rg2)));
+    let store_word_instr = Instruction::StoreWord(ITypeArgs::new(
+        0,
+        Some(Register::Rg2),
+        Some(Register::Rg1),
+    ));
 
     store_word_instr.execute(&mut cpu);
     assert_eq!(cpu.memory.read_word(addr), 0x1234_5678);
@@ -307,7 +325,8 @@ fn test_increment_instruction() {
     let mut cpu = create_test_processor();
     *cpu.reg(Register::Rg1) = 42;
 
-    let inc_instr = Instruction::Increment(RTypeArgs::new(Some(Register::Rg1), None, None, None));
+    let inc_instr =
+        Instruction::Increment(RTypeArgs::new(Some(Register::Rg1), None, None, None));
 
     inc_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg1), 43);
@@ -318,7 +337,8 @@ fn test_decrement_instruction() {
     let mut cpu = create_test_processor();
     *cpu.reg(Register::Rg1) = 42;
 
-    let dec_instr = Instruction::Decrement(RTypeArgs::new(Some(Register::Rg1), None, None, None));
+    let dec_instr =
+        Instruction::Decrement(RTypeArgs::new(Some(Register::Rg1), None, None, None));
 
     dec_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg1), 41);
@@ -377,8 +397,11 @@ fn test_shift_left_with_register() {
 fn test_load_lower_immediate() {
     let mut cpu = create_test_processor();
 
-    let lli_instr =
-        Instruction::LoadLowerImmediate(ITypeArgs::new(0x1234, Some(Register::Rg1), None));
+    let lli_instr = Instruction::LoadLowerImmediate(ITypeArgs::new(
+        0x1234,
+        Some(Register::Rg1),
+        None,
+    ));
 
     lli_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg1), 0x0000_1234);
@@ -389,8 +412,11 @@ fn test_load_upper_immediate() {
     let mut cpu = create_test_processor();
     *cpu.reg(Register::Rg1) = 0x0000_5678;
 
-    let lui_instr =
-        Instruction::LoadUpperImmediate(ITypeArgs::new(0x1234, Some(Register::Rg1), None));
+    let lui_instr = Instruction::LoadUpperImmediate(ITypeArgs::new(
+        0x1234,
+        Some(Register::Rg1),
+        None,
+    ));
 
     lui_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Rg1), 0x1234_5678);
@@ -415,7 +441,8 @@ fn test_jump_equal_when_flag_set() {
     cpu.set_flag(Flag::Equal, true);
     *cpu.reg(Register::Rg1) = 0x1000;
 
-    let jump_eq_instr = Instruction::JumpEq(ITypeArgs::new(0x100, Some(Register::Rg1), None));
+    let jump_eq_instr =
+        Instruction::JumpEq(ITypeArgs::new(0x100, Some(Register::Rg1), None));
 
     jump_eq_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Pcx), 0x1100);
@@ -428,7 +455,8 @@ fn test_jump_equal_when_flag_not_set() {
     *cpu.reg(Register::Rg1) = 0x1000;
     let initial_pc = cpu.get(Register::Pcx);
 
-    let jump_eq_instr = Instruction::JumpEq(ITypeArgs::new(0x100, Some(Register::Rg1), None));
+    let jump_eq_instr =
+        Instruction::JumpEq(ITypeArgs::new(0x100, Some(Register::Rg1), None));
 
     jump_eq_instr.execute(&mut cpu);
     assert_eq!(cpu.get(Register::Pcx), initial_pc);