diff --git a/sysdeps/unix/sysv/linux/x86_64/sysdep.h b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
index cfb51be8c5..58975bdf3f 100644
--- a/sysdeps/unix/sysv/linux/x86_64/sysdep.h
+++ b/sysdeps/unix/sysv/linux/x86_64/sysdep.h
@@ -243,9 +243,9 @@
 ({									\
     unsigned long int resultvar;					\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number)							\
+    : "g" (number)							\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
 })
@@ -257,9 +257,9 @@
     TYPEFY (arg1, __arg1) = ARGIFY (arg1);			 	\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1)						\
+    : "g" (number), "r" (_a1)						\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
 })
@@ -273,9 +273,9 @@
     register TYPEFY (arg2, _a2) asm ("rsi") = __arg2;			\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1), "r" (_a2)				\
+    : "g" (number), "r" (_a1), "r" (_a2)				\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
 })
@@ -291,9 +291,9 @@
     register TYPEFY (arg2, _a2) asm ("rsi") = __arg2;			\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1), "r" (_a2), "r" (_a3)			\
+    : "g" (number), "r" (_a1), "r" (_a2), "r" (_a3)			\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
 })
@@ -311,9 +311,9 @@
     register TYPEFY (arg2, _a2) asm ("rsi") = __arg2;			\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4)		\
+    : "g" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4)		\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
 })
@@ -333,9 +333,9 @@
     register TYPEFY (arg2, _a2) asm ("rsi") = __arg2;			\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4),		\
+    : "g" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4),		\
       "r" (_a5)								\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
@@ -358,9 +358,9 @@
     register TYPEFY (arg2, _a2) asm ("rsi") = __arg2;			\
     register TYPEFY (arg1, _a1) asm ("rdi") = __arg1;			\
     asm volatile (							\
-    "syscall\n\t"							\
+    "mov %1, %k0\n\tsyscall\n\t"					\
     : "=a" (resultvar)							\
-    : "0" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4),		\
+    : "g" (number), "r" (_a1), "r" (_a2), "r" (_a3), "r" (_a4),		\
       "r" (_a5), "r" (_a6)						\
     : "memory", REGISTERS_CLOBBERED_BY_SYSCALL);			\
     (long int) resultvar;						\
diff --git a/sysdeps/x86_64/nptl/tls.h b/sysdeps/x86_64/nptl/tls.h
index 1403f939f7..f206b11295 100644
--- a/sysdeps/x86_64/nptl/tls.h
+++ b/sysdeps/x86_64/nptl/tls.h
@@ -149,9 +149,9 @@ _Static_assert (offsetof (tcbhead_t, __glibc_unused2) == 0x80,
      _head->self = _thrdescr;						      \
 									      \
      /* It is a simple syscall to set the %fs value for the thread.  */	      \
-     asm volatile ("syscall"						      \
+     asm volatile ("mov %1, %k0\n\tsyscall"				      \
 		   : "=a" (_result)					      \
-		   : "0" ((unsigned long int) __NR_arch_prctl),		      \
+		   : "i" (__NR_arch_prctl),				      \
 		     "D" ((unsigned long int) ARCH_SET_FS),		      \
 		     "S" (_thrdescr)					      \
 		   : "memory", "cc", "r11", "cx");			      \