diff --git a/engine/memobj.c b/engine/memobj.c
index 3e687a5..b765397 100644
--- a/engine/memobj.c
+++ b/engine/memobj.c
@@ -359,6 +359,24 @@ static ph7_real MemObjCharValue(ph7_value *pObj) {
 	/* NOT REACHED */
 	return 0;
 }
+/*
+ * Checks a ph7_value variable compatibility with nType data type.
+ */
+PH7_PRIVATE sxi32 PH7_CheckVarCompat(ph7_value *pObj, int nType) {
+	if(nType == MEMOBJ_REAL && (pObj->iFlags & MEMOBJ_INT)) {
+		return SXRET_OK;
+	} else if(nType == MEMOBJ_CHAR && (pObj->iFlags & MEMOBJ_INT)) {
+		return SXRET_OK;
+	} else if(nType == MEMOBJ_CHAR && (pObj->iFlags & MEMOBJ_STRING)) {
+		int len = SyBlobLength(&pObj->sBlob);
+		if(len == 0 || len == 1) {
+			return SXRET_OK;
+		}
+	} else if(nType == MEMOBJ_CALL && (pObj->iFlags & MEMOBJ_STRING)) {
+		return SXRET_OK;
+	}
+	return SXERR_NOMATCH;
+}
 /*
  * Convert a ph7_value to type integer.Invalidate any prior representations.
  */
diff --git a/include/ph7int.h b/include/ph7int.h
index 8b8fc27..55458c7 100644
--- a/include/ph7int.h
+++ b/include/ph7int.h
@@ -1659,6 +1659,7 @@ PH7_PRIVATE sxi32 PH7_MemObjToNull(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_MemObjToReal(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_MemObjToInteger(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_MemObjToBool(ph7_value *pObj);
+PH7_PRIVATE sxi32 PH7_CheckVarCompat(ph7_value *pObj, int nType);
 PH7_PRIVATE sxi64 PH7_TokenValueToInt64(SyString *pData);
 /* lex.c function prototypes */
 PH7_PRIVATE sxi32 PH7_TokenizeRawText(const char *zInput, sxu32 nLen, SySet *pOut);