diff --git a/hermit/arch/x86/kernel/entry.asm b/hermit/arch/x86/kernel/entry.asm
index fc5e50681..f03e0a152 100644
--- a/hermit/arch/x86/kernel/entry.asm
+++ b/hermit/arch/x86/kernel/entry.asm
@@ -545,23 +545,28 @@ isrsyscall:
     push rdi
     push rsi
 
+    ; push system call number  
+    push rax 
+
     ; get kernel stack
     call get_kernel_stack
 
     ; restore registers
-    mov r8,  [rsp+56]
-    mov r9,  [rsp+48]
-    mov r10, [rsp+40]
-    mov r11, [rsp+32]
-    mov rdx, [rsp+24]
+    mov r8,  [rsp+64]
+    mov r9,  [rsp+56]
+    mov r10, [rsp+48]
+    mov r11, [rsp+40]
+    mov rdx, [rsp+32]
     ; see below
-    ; mov rcx, [rsp+16] 
-    mov rdi, [rsp+8]
-    mov rsi, [rsp+0]
+    ; mov rcx, [rsp+24] 
+    mov rdi, [rsp+16]
+    mov rsi, [rsp+8]
 
     xchg rsp, rax ; => rax contains pointer to the kernel stack
+    push rax	  ; store user-level stack pointer
 
-    push rax ; contains original rsp
+    ; restore system call number
+    mov rax, [rax+0]
 
     ; syscall stores in rcx the return address
     ; => using of r10 for the temporary storage of the 4th argument
@@ -569,14 +574,16 @@ isrsyscall:
 
     ; during a system call, HermitCore allows interrupts
     sti
-    call syscall_handler
+    extern syscall_table
+    call [rax*8+syscall_table]
     cli
 
-    ; restore user-level stack
+    ; restore user-level stack pointer
     pop r10
     mov rsp, r10
 
     ; restore registers
+    add rsp, 8 ; ignore old value of rax
     pop rsi
     pop rdi
     pop rcx
diff --git a/hermit/include/hermit/syscall.h b/hermit/include/hermit/syscall.h
index 1883de984..eb40abd27 100644
--- a/hermit/include/hermit/syscall.h
+++ b/hermit/include/hermit/syscall.h
@@ -47,33 +47,33 @@ extern "C" {
 #define __NR_open		2
 #define __NR_close		3
 #define __NR_read		4
-#define __NR_lseek		6
-#define __NR_unlink		7
-#define __NR_getpid		8
-#define __NR_kill		9
-#define __NR_fstat		10
-#define __NR_sbrk		11
-#define __NR_fork		12
-#define __NR_wait		13
-#define __NR_execve		14
-#define __NR_times		15
-#define __NR_accept		16
-#define __NR_bind		17
-#define __NR_closesocket	18
-#define __NR_connect		19
-#define __NR_listen		20
-#define __NR_recv		21
-#define __NR_send		22
-#define __NR_socket		23
-#define __NR_getsockopt		24
-#define __NR_setsockopt		25
-#define __NR_gethostbyname	26
-#define __NR_sendto		27
-#define __NR_recvfrom		28
-#define __NR_select		29
-#define __NR_stat		30
-#define __NR_dup		31
-#define __NR_dup2		32
+#define __NR_lseek		5
+#define __NR_unlink		6
+#define __NR_getpid		7
+#define __NR_kill		8
+#define __NR_fstat		9
+#define __NR_sbrk		10
+#define __NR_fork		11
+#define __NR_wait		12
+#define __NR_execve		13
+#define __NR_times		14
+#define __NR_accept		15
+#define __NR_bind		16
+#define __NR_closesocket	17
+#define __NR_connect		18
+#define __NR_listen		19
+#define __NR_recv		20
+#define __NR_send		21
+#define __NR_socket		22
+#define __NR_getsockopt		23
+#define __NR_setsockopt		24
+#define __NR_gethostbyname	25
+#define __NR_sendto		26
+#define __NR_recvfrom		27
+#define __NR_select		28
+#define __NR_stat		29
+#define __NR_dup		30
+#define __NR_dup2		31
 
 #ifdef __cplusplus
 }
diff --git a/hermit/kernel/syscall.c b/hermit/kernel/syscall.c
index 32355700c..eae55cdcc 100644
--- a/hermit/kernel/syscall.c
+++ b/hermit/kernel/syscall.c
@@ -73,46 +73,55 @@ static ssize_t sys_sbrk(int incr)
 	return ret;
 }
 
-ssize_t syscall_handler(uint32_t sys_nr, ...)
+static int sys_open(const char* name, int flags, int mode)
 {
-	ssize_t ret = -EINVAL;
-	va_list vl;
-
-	check_workqueues();
-
-	va_start(vl, sys_nr);
-
-	switch(sys_nr)
-	{
-	case __NR_exit:
-		sys_exit(va_arg(vl, uint32_t));
-		ret = 0;
-		break;
-	case __NR_write: {
-		int fd = va_arg(vl, int);
-		const char* buf = va_arg(vl, const char*);
-		size_t len = va_arg(vl, size_t);
-		ret = sys_write(fd, buf, len);
-		break;
-	}
-	//TODO: Currently, we ignore file descriptors
-	case __NR_open:
-	case __NR_close:
-		ret = 0;
-		break;
-	case __NR_sbrk: {
-		int incr = va_arg(vl, int);
-
-		ret = sys_sbrk(incr);
-		break;
-	}
-	default:
-		kprintf("invalid system call: 0x%lx\n", sys_nr);
-		ret = -ENOSYS;
-		break;
-	};
-
-	va_end(vl);
-
-	return ret;
+	return 0;
 }
+
+static int sys_close(int fd)
+{
+	return 0;
+}
+
+static int default_handler(void)
+{
+	kprintf("Invalid system call\n");
+
+	return -ENOSYS;
+}
+
+size_t syscall_table[] = {
+	(size_t) sys_exit,		/* __NR_exit 	*/
+	(size_t) sys_write,		/* __NR_write 	*/
+	(size_t) sys_open, 		/* __NR_open 	*/
+	(size_t) sys_close,		/* __NR_close 	*/
+	(size_t) default_handler,	/* __NR_read 	*/
+	(size_t) default_handler,	/* __NR_lseek	*/
+	(size_t) default_handler, 	/* __NR_unlink	*/
+	(size_t) default_handler, 	/* __NR_getpid	*/
+	(size_t) default_handler,	/* __NR_kill	*/
+	(size_t) default_handler,	/* __NR_fstat	*/
+	(size_t) sys_sbrk,		/* __NR_sbrk	*/
+	(size_t) default_handler,	/* __NR_fork	*/
+	(size_t) default_handler,	/* __NR_wait	*/
+	(size_t) default_handler,	/* __NR_execve	*/
+	(size_t) default_handler,	/* __NR_times	*/
+	(size_t) default_handler,	/* __NR_accept	*/
+	(size_t) default_handler,	/* __NR_bind	*/
+	(size_t) default_handler,	/* __NR_closesocket	*/
+	(size_t) default_handler,	/* __NR_connect	*/
+	(size_t) default_handler,	/* __NR_listen	*/
+	(size_t) default_handler,	/* __NR_recv	*/
+	(size_t) default_handler,	/* __NR_send	*/
+	(size_t) default_handler,	/* __NR_socket	*/
+	(size_t) default_handler,	/* __NR_getsockopt	*/
+	(size_t) default_handler,	/* __NR_setsockopt	*/
+	(size_t) default_handler, 	/* __NR_gethostbyname	*/
+	(size_t) default_handler,	/* __NR_sendto	*/
+	(size_t) default_handler,	/* __NR_recvfrom	*/
+	(size_t) default_handler,	/* __NR_select	*/
+	(size_t) default_handler,	/* __NR_stat	*/
+	(size_t) default_handler,	/* __NR_dup	*/
+	(size_t) default_handler,	/* __NR_dup2	*/
+
+};