diff --git a/engine/vm.c b/engine/vm.c
index 7a1c7ea..76e0dbc 100644
--- a/engine/vm.c
+++ b/engine/vm.c
@@ -2936,6 +2936,7 @@ static sxi32 VmByteCodeExec(
 			 */
 			case PH7_OP_MUL:
 			case PH7_OP_MUL_STORE: {
+					SyString sName;
 					ph7_value *pNos = &pTos[-1];
 					/* Force the operand to be numeric */
 					if(pNos < pStack) {
@@ -2974,7 +2975,10 @@ static sxi32 VmByteCodeExec(
 						if(pTos->nIdx == SXU32_HIGH) {
 							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 						} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-							PH7_MemObjStore(pNos, pObj);
+							if(PH7_MemObjSafeStore(pNos, pObj) != SXRET_OK) {
+								SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
+								PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
+							};
 						}
 					}
 					VmPopOperand(&pTos, 1);
@@ -3027,11 +3031,10 @@ static sxi32 VmByteCodeExec(
 						if(pTos->nIdx == SXU32_HIGH) {
 							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 						} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-							if(pNos->nType != pObj->nType && PH7_CheckVarCompat(pNos, pObj->nType) != SXRET_OK) {
+							if(PH7_MemObjSafeStore(pNos, pObj) != SXRET_OK) {
 								SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
 								PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
 							};
-							PH7_MemObjStore(pNos, pObj);
 						}
 					}
 					VmPopOperand(&pTos, 1);
@@ -3084,6 +3087,7 @@ static sxi32 VmByteCodeExec(
 			 * and push the result back onto the stack.
 			 */
 			case PH7_OP_ADD_STORE: {
+					SyString sName;
 					ph7_value *pNos = &pTos[-1];
 					ph7_value *pObj;
 					if(pNos < pStack) {
@@ -3107,7 +3111,10 @@ static sxi32 VmByteCodeExec(
 					if(pTos->nIdx == SXU32_HIGH) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 					} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-						PH7_MemObjStore(pTos, pObj);
+						if(PH7_MemObjSafeStore(pTos, pObj) != SXRET_OK) {
+							SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
+							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
+						};
 					}
 					/* Ticket 1433-35: Perform a stack dup */
 					PH7_MemObjStore(pTos, pNos);
@@ -3160,6 +3167,7 @@ static sxi32 VmByteCodeExec(
 			 * top of the stack) and push the result back onto the stack.
 			 */
 			case PH7_OP_SUB_STORE: {
+					SyString sName;
 					ph7_value *pNos = &pTos[-1];
 					ph7_value *pObj;
 					if(pNos < pStack) {
@@ -3193,7 +3201,10 @@ static sxi32 VmByteCodeExec(
 					if(pTos->nIdx == SXU32_HIGH) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 					} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-						PH7_MemObjStore(pNos, pObj);
+						if(PH7_MemObjSafeStore(pNos, pObj) != SXRET_OK) {
+							SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
+							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
+						};
 					}
 					VmPopOperand(&pTos, 1);
 					break;
@@ -3245,6 +3256,7 @@ static sxi32 VmByteCodeExec(
 			 * Note: Only integer arithemtic is allowed.
 			 */
 			case PH7_OP_MOD_STORE: {
+					SyString sName;
 					ph7_value *pNos = &pTos[-1];
 					ph7_value *pObj;
 					sxi64 a, b, r;
@@ -3273,7 +3285,10 @@ static sxi32 VmByteCodeExec(
 					if(pTos->nIdx == SXU32_HIGH) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 					} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-						PH7_MemObjStore(pNos, pObj);
+						if(PH7_MemObjSafeStore(pNos, pObj) != SXRET_OK) {
+							SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
+							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
+						};
 					}
 					VmPopOperand(&pTos, 1);
 					break;
@@ -3322,6 +3337,7 @@ static sxi32 VmByteCodeExec(
 			 * Note: Only floating point arithemtic is allowed.
 			 */
 			case PH7_OP_DIV_STORE: {
+					SyString sName;
 					ph7_value *pNos = &pTos[-1];
 					ph7_value *pObj;
 					ph7_real a, b, r;
@@ -3350,7 +3366,10 @@ static sxi32 VmByteCodeExec(
 					if(pTos->nIdx == SXU32_HIGH) {
 						PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot perform assignment on a constant class attribute");
 					} else if((pObj = (ph7_value *)SySetAt(&pVm->aMemObj, pTos->nIdx)) != 0) {
-						PH7_MemObjStore(pNos, pObj);
+						if(PH7_MemObjSafeStore(pNos, pObj) != SXRET_OK) {
+							SyStringInitFromBuf(&sName, pInstr->p3, SyStrlen((const char *)pInstr->p3));
+							PH7_VmThrowError(&(*pVm), PH7_CTX_ERR, "Cannot assign a value of incompatible type to variable '$%z'", &sName);
+						};
 					}
 					VmPopOperand(&pTos, 1);
 					break;