diff --git a/src/cpu/core_full/optable.h b/src/cpu/core_full/optable.h
index 1d21d4b5..93c51057 100644
--- a/src/cpu/core_full/optable.h
+++ b/src/cpu/core_full/optable.h
@@ -528,7 +528,7 @@ static OpCode OpCodeTable[1024]={
 /* 0x2f0 - 0x2f7 */
 {D_LOCK		,0			,0		,0		},{D_ICEBP	,0			,0		,0		},
 {L_PREREPNE	,0			,0		,0		},{L_PREREP	,0			,0		,0		},
-{0			,0			,0		,0		},{D_CMC	,0			,0		,0		},
+{D_HLT		,0			,0		,0		},{D_CMC	,0			,0		,0		},
 {L_MODRM	,8			,0		,M_GRP	},{L_MODRM	,0xa		,0		,M_GRP	},
 /* 0x2f8 - 0x2ff */
 {D_CLC		,0			,0		,0		},{D_STC	,0			,0		,0		},
diff --git a/src/cpu/core_normal/prefix_0f.h b/src/cpu/core_normal/prefix_0f.h
index 0f229830..16397144 100644
--- a/src/cpu/core_normal/prefix_0f.h
+++ b/src/cpu/core_normal/prefix_0f.h
@@ -344,7 +344,9 @@
 		break;
 	CASE_0F_W(0xb2)												/* LSS Ew */
 		{	
-			GetRMrw;GetEAa;
+			GetRMrw;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(ss,LoadMw(eaa+2))) RUNEXCEPTION();
 			*rmrw=LoadMw(eaa);
 			break;
@@ -367,14 +369,18 @@
 		}
 	CASE_0F_W(0xb4)												/* LFS Ew */
 		{	
-			GetRMrw;GetEAa;
+			GetRMrw;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(fs,LoadMw(eaa+2))) RUNEXCEPTION();
 			*rmrw=LoadMw(eaa);
 			break;
 		}
 	CASE_0F_W(0xb5)												/* LGS Ew */
 		{	
-			GetRMrw;GetEAa;
+			GetRMrw;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(gs,LoadMw(eaa+2))) RUNEXCEPTION();
 			*rmrw=LoadMw(eaa);
 			break;
diff --git a/src/cpu/core_normal/prefix_66.h b/src/cpu/core_normal/prefix_66.h
index f2aef294..473248e1 100644
--- a/src/cpu/core_normal/prefix_66.h
+++ b/src/cpu/core_normal/prefix_66.h
@@ -462,14 +462,18 @@
 		continue;
 	CASE_D(0xc4)												/* LES */
 		{	
-			GetRMrd;GetEAa;
+			GetRMrd;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(es,LoadMw(eaa+4))) RUNEXCEPTION();
 			*rmrd=LoadMd(eaa);
 			break;
 		}
 	CASE_D(0xc5)												/* LDS */
 		{	
-			GetRMrd;GetEAa;
+			GetRMrd;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(ds,LoadMw(eaa+4))) RUNEXCEPTION();
 			*rmrd=LoadMd(eaa);
 			break;
diff --git a/src/cpu/core_normal/prefix_66_0f.h b/src/cpu/core_normal/prefix_66_0f.h
index 8c00c268..6c5318cd 100644
--- a/src/cpu/core_normal/prefix_66_0f.h
+++ b/src/cpu/core_normal/prefix_66_0f.h
@@ -237,7 +237,9 @@
 		}
 	CASE_0F_D(0xb2)												/* LSS Ed */
 		{	
-			GetRMrd;GetEAa;
+			GetRMrd;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(ss,LoadMw(eaa+4))) RUNEXCEPTION();
 			*rmrd=LoadMd(eaa);
 			break;
@@ -260,14 +262,18 @@
 		}
 	CASE_0F_D(0xb4)												/* LFS Ed */
 		{	
-			GetRMrd;GetEAa;
+			GetRMrd;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(fs,LoadMw(eaa+4))) RUNEXCEPTION();
 			*rmrd=LoadMd(eaa);
 			break;
 		}
 	CASE_0F_D(0xb5)												/* LGS Ed */
 		{	
-			GetRMrd;GetEAa;
+			GetRMrd;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(gs,LoadMw(eaa+4))) RUNEXCEPTION();
 			*rmrd=LoadMd(eaa);
 			break;
diff --git a/src/cpu/core_normal/prefix_none.h b/src/cpu/core_normal/prefix_none.h
index 9622294f..deeeba3c 100644
--- a/src/cpu/core_normal/prefix_none.h
+++ b/src/cpu/core_normal/prefix_none.h
@@ -687,14 +687,18 @@
 		continue;
 	CASE_W(0xc4)												/* LES */
 		{	
-			GetRMrw;GetEAa;
+			GetRMrw;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(es,LoadMw(eaa+2))) RUNEXCEPTION();
 			*rmrw=LoadMw(eaa);
 			break;
 		}
 	CASE_W(0xc5)												/* LDS */
 		{	
-			GetRMrw;GetEAa;
+			GetRMrw;
+			if (rm >= 0xc0) goto illegal_opcode;
+			GetEAa;
 			if (CPU_SetSegGeneral(ds,LoadMw(eaa+2))) RUNEXCEPTION();
 			*rmrw=LoadMw(eaa);
 			break;