diff --git a/insns.dat b/insns.dat
index 54a87ef0..7a1a696a 100644
--- a/insns.dat
+++ b/insns.dat
@@ -770,12 +770,18 @@ MFENCE		void				\3\x0F\xAE\xF0					X64,AMD
 MONITOR		void				\3\x0F\x01\xC8					PRESCOTT
 MONITOR		reg_eax,reg_ecx,reg_edx		\3\x0F\x01\xC8					PRESCOTT,ND
 MONITOR		reg_rax,reg_ecx,reg_edx		\3\x0F\x01\xC8					X64,ND
-MOV		mem,reg_sreg			\1\x8C\101					8086,SM
+MOV		mem,reg_sreg			\1\x8C\101					8086,SW
 MOV		reg16,reg_sreg			\320\1\x8C\101					8086
 MOV		reg32,reg_sreg			\321\1\x8C\101					386
-MOV		reg_sreg,mem			\1\x8E\110					8086,SM
-MOV		reg_sreg,reg16			\1\x8E\110					8086
-MOV		reg_sreg,reg32			\1\x8E\110					386
+MOV		reg64,reg_sreg			\323\1\x8C\101					X64,OPT,ND
+MOV		rm64,reg_sreg			\324\1\x8C\101					X64
+MOV		reg_sreg,mem			\1\x8E\110					8086,SW
+MOV		reg_sreg,reg16			\1\x8E\110					8086,OPT,ND
+MOV		reg_sreg,reg32			\1\x8E\110					386,OPT,ND
+MOV		reg_sreg,reg64			\323\1\x8E\110					X64,OPT,ND
+MOV		reg_sreg,reg16			\320\1\x8E\110					8086
+MOV		reg_sreg,reg32			\321\1\x8E\110					386
+MOV		reg_sreg,rm64			\324\1\x8E\110					X64
 MOV		reg_al,mem_offs			\1\xA0\45					8086,SM
 MOV		reg_ax,mem_offs			\320\1\xA1\45					8086,SM
 MOV		reg_eax,mem_offs		\321\1\xA1\45					386,SM
diff --git a/test/sreg.asm b/test/sreg.asm
new file mode 100644
index 00000000..11449a50
--- /dev/null
+++ b/test/sreg.asm
@@ -0,0 +1,65 @@
+	bits 64
+	mov es,rax
+	mov ss,rax
+	mov ds,rax
+	mov fs,rax
+	mov gs,rax
+	mov es,eax
+	mov ss,eax
+	mov ds,eax
+	mov fs,eax
+	mov gs,eax
+	mov es,ax
+	mov ss,ax
+	mov ds,ax
+	mov fs,ax
+	mov gs,ax
+	mov es,[rsi]
+	mov ss,[rsi]
+	mov ds,[rsi]
+	mov fs,[rsi]
+	mov gs,[rsi]
+	mov es,word [rsi]
+	mov ss,word [rsi]
+	mov ds,word [rsi]
+	mov fs,word [rsi]
+	mov gs,word [rsi]
+	mov es,qword [rsi]
+	mov ss,qword [rsi]
+	mov ds,qword [rsi]
+	mov fs,qword [rsi]
+	mov gs,qword [rsi]
+	mov rax,es
+	mov rax,cs
+	mov rax,ss
+	mov rax,ds
+	mov rax,fs
+	mov rax,gs
+	mov eax,es
+	mov eax,ss
+	mov eax,ds
+	mov eax,fs
+	mov eax,fs
+	mov ax,es
+	mov ax,ss
+	mov ax,ds
+	mov ax,fs
+	mov ax,gs
+	mov [rdi],es
+	mov [rdi],cs
+	mov [rdi],ss
+	mov [rdi],ds
+	mov [rdi],fs
+	mov [rdi],gs
+	mov word [rdi],es
+	mov word [rdi],cs
+	mov word [rdi],ss
+	mov word [rdi],ds
+	mov word [rdi],fs
+	mov word [rdi],gs
+	mov qword [rdi],es
+	mov qword [rdi],cs
+	mov qword [rdi],ss
+	mov qword [rdi],ds
+	mov qword [rdi],fs
+	mov qword [rdi],gs