diff --git a/base/usr/include/sys/uregs.h b/base/usr/include/sys/uregs.h
index 31498bc9..f55c2dc3 100644
--- a/base/usr/include/sys/uregs.h
+++ b/base/usr/include/sys/uregs.h
@@ -9,11 +9,11 @@ _Begin_C_Header
 # include <kernel/arch/x86_64/regs.h>
 # define uregs_syscall_result(r) ((r)->rax)
 # define uregs_syscall_num(r)    ((r)->rax)
-# define uregs_syscall_arg1(r)   ((r)->rbx)
-# define uregs_syscall_arg2(r)   ((r)->rcx)
+# define uregs_syscall_arg1(r)   ((r)->rdi)
+# define uregs_syscall_arg2(r)   ((r)->rsi)
 # define uregs_syscall_arg3(r)   ((r)->rdx)
-# define uregs_syscall_arg4(r)   ((r)->rsi)
-# define uregs_syscall_arg5(r)   ((r)->rdi)
+# define uregs_syscall_arg4(r)   ((r)->r10)
+# define uregs_syscall_arg5(r)   ((r)->r8)
 # define uregs_ip(r)             ((r)->rip)
 # define uregs_bp(r)             ((r)->rbp)
 # define UREGS_FMT \
diff --git a/base/usr/include/syscall.h b/base/usr/include/syscall.h
index 2585bb83..f13d9340 100644
--- a/base/usr/include/syscall.h
+++ b/base/usr/include/syscall.h
@@ -24,7 +24,7 @@ _Begin_C_Header
 	long syscall_##fn(P1 p1) { \
 		long __res = num; __asm__ __volatile__("int $0x7F" \
 				: "=a" (__res) \
-				: "a" (__res), "b" ((long)(p1))); \
+				: "a" (__res), "D" ((long)(p1))); \
 		return __res; \
 	}
 
@@ -32,7 +32,7 @@ _Begin_C_Header
 	long syscall_##fn(P1 p1, P2 p2) { \
 		long __res = num; __asm__ __volatile__("int $0x7F" \
 				: "=a" (__res) \
-				: "a" (__res), "b" ((long)(p1)), "c"((long)(p2))); \
+				: "a" (__res), "D" ((long)(p1)), "S"((long)(p2))); \
 		return __res; \
 	}
 
@@ -40,23 +40,26 @@ _Begin_C_Header
 	long syscall_##fn(P1 p1, P2 p2, P3 p3) { \
 		long __res = num; __asm__ __volatile__("int $0x7F" \
 				: "=a" (__res) \
-				: "a" (__res), "b" ((long)(p1)), "c"((long)(p2)), "d"((long)(p3))); \
+				: "a" (__res), "D" ((long)(p1)), "S"((long)(p2)), "d"((long)(p3))); \
 		return __res; \
 	}
 
 #define DEFN_SYSCALL4(fn, num, P1, P2, P3, P4) \
 	long syscall_##fn(P1 p1, P2 p2, P3 p3, P4 p4) { \
+		register long p4_ __asm__("r10") = (long)p4; \
 		long __res = num; __asm__ __volatile__("int $0x7F" \
 				: "=a" (__res) \
-				: "a" (__res), "b" ((long)(p1)), "c"((long)(p2)), "d"((long)(p3)), "S"((long)(p4))); \
+				: "a" (__res), "D" ((long)(p1)), "S"((long)(p2)), "d"((long)(p3)), "r"((long)(p4_))); \
 		return __res; \
 	}
 
 #define DEFN_SYSCALL5(fn, num, P1, P2, P3, P4, P5) \
 	long syscall_##fn(P1 p1, P2 p2, P3 p3, P4 p4, P5 p5) { \
+		register long p4_ __asm__("r10") = (long)p4; \
+		register long p5_ __asm__("r8") = (long)p5; \
 		long __res = num; __asm__ __volatile__("int $0x7F" \
 				: "=a" (__res) \
-				: "a" (__res), "b" ((long)(p1)), "c"((long)(p2)), "d"((long)(p3)), "S"((long)(p4)), "D"((long)(p5))); \
+				: "a" (__res), "D" ((long)(p1)), "S"((long)(p2)), "d"((long)(p3)), "r"((long)(p4_)), "r"((long)(p5_))); \
 		return __res; \
 	}
 #elif defined(__aarch64__)
diff --git a/kernel/arch/x86_64/user.c b/kernel/arch/x86_64/user.c
index 880af670..4fe95ea5 100644
--- a/kernel/arch/x86_64/user.c
+++ b/kernel/arch/x86_64/user.c
@@ -281,10 +281,10 @@ long arch_reboot(void) {
 /* Syscall parameter accessors */
 void arch_syscall_return(struct regs * r, long retval) { r->rax = retval; }
 long arch_syscall_number(struct regs * r) { return (unsigned long)r->rax; }
-long arch_syscall_arg0(struct regs * r) { return r->rbx; }
-long arch_syscall_arg1(struct regs * r) { return r->rcx; }
+long arch_syscall_arg0(struct regs * r) { return r->rdi; }
+long arch_syscall_arg1(struct regs * r) { return r->rsi; }
 long arch_syscall_arg2(struct regs * r) { return r->rdx; }
-long arch_syscall_arg3(struct regs * r) { return r->rsi; }
-long arch_syscall_arg4(struct regs * r) { return r->rdi; }
+long arch_syscall_arg3(struct regs * r) { return r->r10; }
+long arch_syscall_arg4(struct regs * r) { return r->r8; }
 long arch_stack_pointer(struct regs * r) { return r->rsp; }
 long arch_user_ip(struct regs * r) { return r->rip; }