diff --git a/kernel/arch/i686/Signal.S b/kernel/arch/i686/Signal.S
index c22d1c4c..633f01bc 100644
--- a/kernel/arch/i686/Signal.S
+++ b/kernel/arch/i686/Signal.S
@@ -7,22 +7,26 @@
 
 .global signal_trampoline
 signal_trampoline:
-	ud2
-
 	pushl %ebp
 	movl %esp, %ebp
-	subl $8, %esp
 
 	pusha
 
 	movl 40(%esp), %edi
 	movl 36(%esp), %eax
 
+	// align stack to 16 bytes
+	movl %esp, %ebx
+	andl $0x0F, %ebx
+	subl %ebx, %esp
+
 	subl $12, %esp
 	pushl %edi
 	call *%eax
 	addl $16, %esp
 
+	// restore stack
+	addl %ebx, %esp
 	popa
 
 	leave
diff --git a/kernel/arch/x86_64/Signal.S b/kernel/arch/x86_64/Signal.S
index afa7095a..5cf22760 100644
--- a/kernel/arch/x86_64/Signal.S
+++ b/kernel/arch/x86_64/Signal.S
@@ -23,12 +23,18 @@ signal_trampoline:
 	pushq %r14
 	pushq %r15
 
-	// This is 16 byte aligned
-
 	movq 128(%rsp), %rdi
 	movq 120(%rsp), %rax
+
+	// align stack to 16 bytes
+	movq %rsp, %rbx
+	andq $0x0F, %rbx
+	subq %rbx, %rsp
+
 	call *%rax
 
+	// restore stack
+	addq %rbx, %rsp
 	popq %r15
 	popq %r14
 	popq %r13
diff --git a/kernel/include/kernel/Thread.h b/kernel/include/kernel/Thread.h
index 8e79d2c2..9da92222 100644
--- a/kernel/include/kernel/Thread.h
+++ b/kernel/include/kernel/Thread.h
@@ -94,7 +94,7 @@ namespace Kernel
 
 	private:
 		static constexpr size_t		m_kernel_stack_size		= PAGE_SIZE * 64;
-		static constexpr size_t		m_userspace_stack_size	= PAGE_SIZE * 4;
+		static constexpr size_t		m_userspace_stack_size	= PAGE_SIZE * 64;
 		BAN::UniqPtr<VirtualRange>	m_kernel_stack;
 		BAN::UniqPtr<VirtualRange>	m_userspace_stack;
 		const pid_t					m_tid				{ 0 };
diff --git a/kernel/kernel/Thread.cpp b/kernel/kernel/Thread.cpp
index 443531ed..d98a13b6 100644
--- a/kernel/kernel/Thread.cpp
+++ b/kernel/kernel/Thread.cpp
@@ -335,7 +335,9 @@ namespace Kernel
 		else if (signal_handler != (vaddr_t)SIG_DFL)
 		{
 			// call userspace signal handlers
+#if ARCH(x86_64)
 			interrupt_stack.sp -= 128; // skip possible red-zone
+#endif
 			write_to_stack(interrupt_stack.sp, interrupt_stack.ip);
 			write_to_stack(interrupt_stack.sp, signal);
 			write_to_stack(interrupt_stack.sp, signal_handler);