diff --git a/src/build/register/RegisterNumber.go b/src/build/register/RegisterNumber.go
index ce9a41f..298c4d7 100644
--- a/src/build/register/RegisterNumber.go
+++ b/src/build/register/RegisterNumber.go
@@ -3,6 +3,7 @@ package register
 import (
 	"git.akyoto.dev/cli/q/src/build/asm"
 	"git.akyoto.dev/cli/q/src/build/cpu"
+	"git.akyoto.dev/cli/q/src/build/sizeof"
 )
 
 func (f *Machine) RegisterNumber(mnemonic asm.Mnemonic, a cpu.Register, b int) {
@@ -10,11 +11,20 @@ func (f *Machine) RegisterNumber(mnemonic asm.Mnemonic, a cpu.Register, b int) {
 		f.SaveRegister(a)
 	}
 
-	f.Assembler.RegisterNumber(mnemonic, a, b)
+	if sizeof.Signed(int64(b)) == 8 {
+		tmp := f.NewRegister()
+		f.Assembler.RegisterNumber(asm.MOVE, tmp, b)
+		f.UseRegister(tmp)
+		f.postInstruction()
+		f.Assembler.RegisterRegister(mnemonic, a, tmp)
+		f.postInstruction()
+		f.FreeRegister(tmp)
+	} else {
+		f.Assembler.RegisterNumber(mnemonic, a, b)
+		f.postInstruction()
+	}
 
 	if mnemonic == asm.MOVE {
 		f.UseRegister(a)
 	}
-
-	f.postInstruction()
 }
diff --git a/tests/programs/64-bit.q b/tests/programs/64-bit.q
new file mode 100644
index 0000000..37e9d42
--- /dev/null
+++ b/tests/programs/64-bit.q
@@ -0,0 +1,12 @@
+main() {
+	x := 20000000000
+	assert x == 20000000000
+	x -= 10000000000
+	assert x == 10000000000
+	x -= 10000000000
+	assert x == 0
+	x -= 10000000000
+	assert x == -10000000000
+	x -= 10000000000
+	assert x == -20000000000
+}
\ No newline at end of file
diff --git a/tests/programs/negation.q b/tests/programs/negation.q
index 94e2826..709f995 100644
--- a/tests/programs/negation.q
+++ b/tests/programs/negation.q
@@ -1,7 +1,10 @@
 main() {
-	assert f(-32) == 32
+	assert neg(-1) == 1
+	assert neg(1) == -1
+	assert neg(-256) == 256
+	assert neg(256) == -256
 }
 
-f(x) {
+neg(x) {
 	return -x
 }
\ No newline at end of file
diff --git a/tests/programs/negative.q b/tests/programs/negative.q
index f300e48..dd0ff3f 100644
--- a/tests/programs/negative.q
+++ b/tests/programs/negative.q
@@ -1,5 +1,17 @@
 main() {
-	a := -32
-	b := 64
-	assert a + b == 32
+	a := -1
+	b := -2
+	assert a == -1
+	assert a != 0xFF
+	assert a != 0xFFFF
+	assert a != 0xFFFFFFFF
+	assert b == -2
+	assert b != 0xFE
+	assert b != 0xFFFE
+	assert b != 0xFFFFFFFE
+	assert a + b == -3
+	assert a - b == 1
+	assert a * b == 2
+	assert a / b == 0
+	assert a % b == -1
 }
\ No newline at end of file
diff --git a/tests/programs/out-of-memory.q b/tests/programs/out-of-memory.q
new file mode 100644
index 0000000..4b7603f
--- /dev/null
+++ b/tests/programs/out-of-memory.q
@@ -0,0 +1,6 @@
+import mem
+
+main() {
+	address := mem.alloc(1024 * 1024 * 1024 * 1024)
+	assert address < 0
+}
\ No newline at end of file
diff --git a/tests/programs_test.go b/tests/programs_test.go
index 6fbc5fe..3406331 100644
--- a/tests/programs_test.go
+++ b/tests/programs_test.go
@@ -51,6 +51,7 @@ var programs = []struct {
 	{"jump-near", "", "", 0},
 	{"loop", "", "", 0},
 	{"loop-lifetime", "", "", 0},
+	{"out-of-memory", "", "", 0},
 }
 
 func TestPrograms(t *testing.T) {