diff --git a/src/core/ExecuteRegisterNumber.go b/src/core/ExecuteRegisterNumber.go
index 77a6ffb..0176f82 100644
--- a/src/core/ExecuteRegisterNumber.go
+++ b/src/core/ExecuteRegisterNumber.go
@@ -25,10 +25,6 @@ func (f *Function) ExecuteRegisterNumber(operation token.Token, register cpu.Reg
 		f.RegisterNumber(asm.MUL, register, number)
 
 	case token.Div, token.DivAssign:
-		if register != x86.RAX {
-			f.SaveRegister(x86.RAX)
-		}
-
 		f.SaveRegister(x86.RDX)
 		tmp := f.NewRegister()
 		f.RegisterNumber(asm.MOVE, tmp, number)
@@ -36,7 +32,6 @@ func (f *Function) ExecuteRegisterNumber(operation token.Token, register cpu.Reg
 		f.FreeRegister(tmp)
 
 	case token.Mod, token.ModAssign:
-		f.SaveRegister(x86.RAX)
 		f.SaveRegister(x86.RDX)
 		tmp := f.NewRegister()
 		f.RegisterNumber(asm.MOVE, tmp, number)
diff --git a/src/core/ExecuteRegisterRegister.go b/src/core/ExecuteRegisterRegister.go
index fc785b7..3e699fb 100644
--- a/src/core/ExecuteRegisterRegister.go
+++ b/src/core/ExecuteRegisterRegister.go
@@ -25,15 +25,10 @@ func (f *Function) ExecuteRegisterRegister(operation token.Token, register cpu.R
 		f.RegisterRegister(asm.MUL, register, operand)
 
 	case token.Div, token.DivAssign:
-		if register != x86.RAX {
-			f.SaveRegister(x86.RAX)
-		}
-
 		f.SaveRegister(x86.RDX)
 		f.RegisterRegister(asm.DIV, register, operand)
 
 	case token.Mod, token.ModAssign:
-		f.SaveRegister(x86.RAX)
 		f.SaveRegister(x86.RDX)
 		f.RegisterRegister(asm.MODULO, register, operand)
 
diff --git a/tests/programs/operator-assign-number.q b/tests/programs/operator-assign-number.q
new file mode 100644
index 0000000..532e409
--- /dev/null
+++ b/tests/programs/operator-assign-number.q
@@ -0,0 +1,17 @@
+main() {
+	f(10)
+}
+
+f(x int) {
+	y := x
+	x -= 2
+	assert x < y
+	x += 2
+	assert x == y
+	x *= 2
+	assert x > y
+	x /= 2
+	assert x == y
+	x %= 2
+	assert x < 2
+}
\ No newline at end of file
diff --git a/tests/programs/operator-assign-variable.q b/tests/programs/operator-assign-variable.q
new file mode 100644
index 0000000..fe73954
--- /dev/null
+++ b/tests/programs/operator-assign-variable.q
@@ -0,0 +1,18 @@
+main() {
+	f(10)
+}
+
+f(x int) {
+	y := x
+	num := 2
+	x -= num
+	assert x < y
+	x += num
+	assert x == y
+	x *= num
+	assert x > y
+	x /= num
+	assert x == y
+	x %= num
+	assert x < num
+}
\ No newline at end of file
diff --git a/tests/programs/operator-assign.q b/tests/programs/operator-assign.q
deleted file mode 100644
index 36809f2..0000000
--- a/tests/programs/operator-assign.q
+++ /dev/null
@@ -1,30 +0,0 @@
-main() {
-	number(10)
-	register(10)
-}
-
-number(x int) {
-	y := x
-	x -= 1
-	assert x < y
-	x += 1
-	assert x == y
-	x *= 2
-	assert x > y
-	x /= 2
-	assert x == y
-}
-
-register(x int) {
-	y := x
-	num := 1
-	x -= num
-	assert x < y
-	x += num
-	assert x == y
-	num = 2
-	x *= num
-	assert x > y
-	x /= num
-	assert x == y
-}
\ No newline at end of file
diff --git a/tests/programs/operator-number.q b/tests/programs/operator-number.q
new file mode 100644
index 0000000..4bafba8
--- /dev/null
+++ b/tests/programs/operator-number.q
@@ -0,0 +1,17 @@
+main() {
+	f(10)
+}
+
+f(x int) {
+	y := x
+	x = x - 2
+	assert x < y
+	x = x + 2
+	assert x == y
+	x = x * 2
+	assert x > y
+	x = x / 2
+	assert x == y
+	x = x % 2
+	assert x < 2
+}
\ No newline at end of file
diff --git a/tests/programs/operator-variable.q b/tests/programs/operator-variable.q
new file mode 100644
index 0000000..abc4d7c
--- /dev/null
+++ b/tests/programs/operator-variable.q
@@ -0,0 +1,18 @@
+main() {
+	f(10)
+}
+
+f(x int) {
+	y := x
+	num := 2
+	x = x - num
+	assert x < y
+	x = x + num
+	assert x == y
+	x = x * num
+	assert x > y
+	x = x / num
+	assert x == y
+	x = x % num
+	assert x < num
+}
\ No newline at end of file
diff --git a/tests/programs_test.go b/tests/programs_test.go
index da5dfc8..6e97a11 100644
--- a/tests/programs_test.go
+++ b/tests/programs_test.go
@@ -28,7 +28,10 @@ var programs = []struct {
 	{"return-multi", 0},
 	{"math", 0},
 	{"precedence", 0},
-	{"operator-assign", 0},
+	{"operator-number", 0},
+	{"operator-variable", 0},
+	{"operator-assign-number", 0},
+	{"operator-assign-variable", 0},
 	{"const", 0},
 	{"escape-rune", 0},
 	{"escape-string", 0},