diff --git a/include/cspublic.h b/include/cspublic.h
index 38d6fb7fa5..f0d3278cba 100644
--- a/include/cspublic.h
+++ b/include/cspublic.h
@@ -613,9 +613,11 @@ enum
 #define CS_IMAGELOCATOR_TYPE   TDS_STATIC_CAST(CS_INT, 38)
 #define CS_UNITEXTLOCATOR_TYPE TDS_STATIC_CAST(CS_INT, 39)
 #define CS_UNIQUE_TYPE         TDS_STATIC_CAST(CS_INT, 40)
+#define CS_NVARCHAR_TYPE       TDS_STATIC_CAST(CS_INT, 41)
+#define CS_NLONGCHAR_TYPE      TDS_STATIC_CAST(CS_INT, 42)
 
 #define CS_MIN_SYBTYPE CS_CHAR_TYPE
-#define CS_MAX_SYBTYPE CS_UNIQUE_TYPE
+#define CS_MAX_SYBTYPE CS_NLONGCHAR_TYPE
 
 #define CS_USER_TYPE        TDS_STATIC_CAST(CS_INT, 100)
 /* cs_dt_info type values */
diff --git a/src/ctlib/cs.c b/src/ctlib/cs.c
index ad89d6130d..1fd48e9d60 100644
--- a/src/ctlib/cs.c
+++ b/src/ctlib/cs.c
@@ -549,7 +549,9 @@ _cs_convert(CS_CONTEXT * ctx, const CS_DATAFMT_COMMON * srcfmt, CS_VOID * srcdat
 		return CS_FAIL;
 	}
 	src_len = srcfmt->maxlength;
-	if (datatype == CS_VARCHAR_TYPE || datatype == CS_VARBINARY_TYPE) {
+	if (datatype == CS_VARCHAR_TYPE ||
+	    datatype == CS_NVARCHAR_TYPE ||
+	    datatype == CS_VARBINARY_TYPE) {
 		CS_VARCHAR *vc = (CS_VARCHAR *) srcdata;
 		src_len = vc->len;
 		srcdata = vc->str;
@@ -562,7 +564,9 @@ _cs_convert(CS_CONTEXT * ctx, const CS_DATAFMT_COMMON * srcfmt, CS_VOID * srcdat
 		return CS_FAIL;
 	}
 	destlen = destfmt->maxlength;
-	if (datatype == CS_VARCHAR_TYPE || datatype == CS_VARBINARY_TYPE) {
+	if (datatype == CS_VARCHAR_TYPE ||
+	    datatype == CS_NVARCHAR_TYPE ||
+	    datatype == CS_VARBINARY_TYPE) {
 		destvc = (CS_VARCHAR *) destdata;
 		destlen  = sizeof(destvc->str);
 		destdata = destvc->str;
@@ -622,6 +626,8 @@ _cs_convert(CS_CONTEXT * ctx, const CS_DATAFMT_COMMON * srcfmt, CS_VOID * srcdat
 		case SYBCHAR:
 		case SYBVARCHAR:
 		case SYBTEXT:
+		case SYBNVARCHAR:
+		case SYBNTEXT:
 			tdsdump_log(TDS_DBG_FUNC, "cs_convert() desttype = character\n");
 
 			memcpy(dest, srcdata, minlen);
@@ -824,6 +830,8 @@ _cs_convert(CS_CONTEXT * ctx, const CS_DATAFMT_COMMON * srcfmt, CS_VOID * srcdat
 	case SYBCHAR:
 	case SYBVARCHAR:
 	case SYBTEXT:
+	case SYBNVARCHAR:
+	case SYBNTEXT:
 		ret = CS_SUCCEED;
 		if (len > destlen) {
 			tdsdump_log(TDS_DBG_FUNC, "Data-conversion resulted in overflow\n");
diff --git a/src/ctlib/ct.c b/src/ctlib/ct.c
index 396048e849..3d965f1e37 100644
--- a/src/ctlib/ct.c
+++ b/src/ctlib/ct.c
@@ -2179,6 +2179,7 @@ _ct_get_server_type(TDSSOCKET *tds, int datatype)
 	case CS_BIT_TYPE:		return SYBBIT;
 	case CS_CHAR_TYPE:		return SYBCHAR;
 	case CS_VARCHAR_TYPE:		return SYBVARCHAR;
+	case CS_NVARCHAR_TYPE:		return SYBNVARCHAR;
 	case CS_LONG_TYPE:
 	case CS_UBIGINT_TYPE:
 		if (!tds || tds_capability_has_req(tds->conn, TDS_REQ_DATA_UINT8))
@@ -2208,11 +2209,12 @@ _ct_get_server_type(TDSSOCKET *tds, int datatype)
 	case CS_TEXT_TYPE:		return SYBTEXT;
 	case CS_UNIQUE_TYPE:		return SYBUNIQUE;
 	case CS_LONGBINARY_TYPE:	return SYBLONGBINARY;
-	case CS_UNICHAR_TYPE:		return SYBVARCHAR;
+	case CS_UNICHAR_TYPE:		return SYBNVARCHAR;
 	case CS_LONGCHAR_TYPE:
 		if (!tds || IS_TDS7_PLUS(tds->conn))
 			return SYBVARCHAR;
 		return SYBLONGCHAR;
+	case CS_NLONGCHAR_TYPE:		return SYBNVARCHAR;
 	case CS_DATE_TYPE:
 		if (!tds || tds_capability_has_req(tds->conn, TDS_REQ_DATA_DATE))
 			return SYBDATE;
@@ -3383,6 +3385,8 @@ ct_param(CS_COMMAND * cmd, CS_DATAFMT * datafmt_arg, CS_VOID * data, CS_INT data
 	CS_PARAM *param;
 	const CS_DATAFMT_LARGE *datafmt;
 	CS_DATAFMT_LARGE datafmt_buf;
+	bool promote = (datafmt_arg->datatype == CS_VARCHAR_TYPE  ||
+			datafmt_arg->datatype == CS_LONGCHAR_TYPE);
 
 	tdsdump_log(TDS_DBG_FUNC, "ct_param(%p, %p, %p, %d, %hd)\n", cmd, datafmt_arg, data, datalen, indicator);
 
@@ -3391,6 +3395,30 @@ ct_param(CS_COMMAND * cmd, CS_DATAFMT * datafmt_arg, CS_VOID * data, CS_INT data
 
 	datafmt = _ct_datafmt_conv_in(cmd->con->ctx, datafmt_arg, &datafmt_buf);
 
+	if (promote  &&	 IS_TDS7_PLUS(cmd->con->tds_socket->conn)) {
+		/* Actually promote only if non-ASCII characters are present */
+		CS_INT i;
+
+		promote = 0;
+		for (i = 0;  i < datalen;  ++i) {
+			if (((const char*)data)[i] & 0x80) {
+				promote = 1;
+				break;
+			}
+		}
+
+		if ( !promote ) {
+			/* pure ASCII, leave as is */
+		} else if (datafmt->datatype == CS_VARCHAR_TYPE) {
+			datafmt_arg->datatype = CS_NVARCHAR_TYPE;
+			datafmt_buf.datatype = CS_NVARCHAR_TYPE;
+		} else if (datafmt->datatype == CS_LONGCHAR_TYPE) {
+			datafmt_arg->datatype = CS_NLONGCHAR_TYPE;
+			datafmt_buf.datatype = CS_NLONGCHAR_TYPE;
+		}
+	}
+
+
 	switch (cmd->command_type) {
 	case CS_RPC_CMD:
 		if (!cmd->rpc) {
@@ -4203,7 +4231,9 @@ paraminfoalloc(TDSSOCKET * tds, CS_PARAM * first_param)
 			temp_datalen = *(p->datalen);
 		}
 
-		if (temp_type == CS_VARCHAR_TYPE || temp_type == CS_VARBINARY_TYPE) {
+		if (temp_type == CS_VARCHAR_TYPE
+		    ||	temp_type == CS_NVARCHAR_TYPE
+		    ||	temp_type == CS_VARBINARY_TYPE) {
 			CS_VARCHAR *vc = (CS_VARCHAR *) temp_value;
 
 			if (vc) {
@@ -4230,6 +4260,13 @@ paraminfoalloc(TDSSOCKET * tds, CS_PARAM * first_param)
 			if (p->maxlen < 0) {
 				tds_free_param_results(params);
 				return NULL;
+			} else if (p->maxlen == 0
+				   &&  is_unicode_type(tds_type)) {
+				/*
+				 * Auto-detect; account for possible
+				 * conversion to UCS-2.
+				 */
+				p->maxlen = temp_datalen * 2;
 			}
 			pcol->on_server.column_size = pcol->column_size = p->maxlen;
 			pcol->column_cur_size = temp_value ? temp_datalen : -1;
diff --git a/src/tds/convert.c b/src/tds/convert.c
index 320c5efdab..9ca8b42c5c 100644
--- a/src/tds/convert.c
+++ b/src/tds/convert.c
@@ -200,8 +200,11 @@ binary_to_result(int desttype, const void *data, size_t len, CONV_RESULT * cr)
 	return (TDS_INT)len;
 }
 
+/* "N" versions are safe to list due to iconv calls elsewhere. */
 #define CASE_ALL_CHAR \
-	SYBCHAR: case SYBVARCHAR: case SYBTEXT: case XSYBCHAR: case XSYBVARCHAR
+	SYBCHAR: case SYBVARCHAR: case SYBTEXT: case XSYBCHAR: \
+	case XSYBVARCHAR: case SYBNVARCHAR: case SYBNTEXT: case XSYBNCHAR: \
+	case XSYBNVARCHAR
 #define CASE_ALL_BINARY \
 	SYBBINARY: case SYBVARBINARY: case SYBIMAGE: case XSYBBINARY: case XSYBVARBINARY: \
 	case SYBLONGBINARY: case TDS_CONVERT_BINARY
@@ -1986,8 +1989,6 @@ tds_convert(const TDSCONTEXT *tds_ctx, int srctype, const void *src, TDS_UINT sr
 	case SYBUNIQUE:
 		length = tds_convert_unique(src, desttype, cr);
 		break;
-	case SYBNVARCHAR:
-	case SYBNTEXT:
 	case SYBMSTABLE:
 	default:
 		return TDS_CONVERT_NOAVAIL;
diff --git a/src/tds/data.c b/src/tds/data.c
index aaab739db3..27637c8773 100644
--- a/src/tds/data.c
+++ b/src/tds/data.c
@@ -247,6 +247,9 @@ tds_set_param_type(TDSCONNECTION * conn, TDSCOLUMN * curcol, TDS_SERVER_TYPE typ
 {
 	if (IS_TDS7_PLUS(conn)) {
 		switch (type) {
+		case SYBNVARCHAR:
+			type = XSYBNVARCHAR;
+			break;
 		case SYBVARCHAR:
 			type = XSYBVARCHAR;
 			break;
diff --git a/src/tds/tds_willconvert.pl b/src/tds/tds_willconvert.pl
index acf1299410..f29f212c11 100755
--- a/src/tds/tds_willconvert.pl
+++ b/src/tds/tds_willconvert.pl
@@ -36,7 +36,8 @@ ($)
 	return qw(DATETIME DATETIME4 DATE TIME MSDATE MSTIME MSDATETIME2 MSDATETIMEOFFSET 5BIGDATETIME 5BIGTIME) if $_ eq 'DATETIMEx';
 	return qw(BIT BITN) if $_ eq 'BITx';
 	return qw(BINARY VARBINARY IMAGE LONGBINARY XBINARY XVARBINARY) if $_ eq 'BINARYx';
-	return qw(CHAR VARCHAR XCHAR XVARCHAR) if $_ eq 'CHARx';
+	return qw(CHAR VARCHAR XCHAR XNCHAR XNVARCHAR XVARCHAR) if $_ eq 'CHARx';
+	return qw(TEXT NTEXT) if $_ eq 'TEXT';
 	return ($_);
 }
 
@@ -129,21 +130,23 @@ ($)
 }
 print "};\n";
 
+# NB: SYBSENSITIVITY (Sybase) == 103 (0x67) == SYBNVARCHAR (MS)
+
 __DATA__
           To
 From
             CHARx TEXT BINARYx INTx FLTx NUMERIC DECIMAL BITx MONEYx DATETIMEx BOUNDARY UNIQUE SENSITIVITY MSTABLE
-CHARx       T     T    T       T    T    T       T       T    T      T         T        T      t           F
-TEXT        T     T    T       T    T    T       T       T    T      T         T        T      t           F
-BINARYx     T     T    T       T    T    F       F       F    T      F         F        F      F           F
-INTx        T     T    T       T    T    T       T       T    T      F         F        F      F           F
-FLTx        T     T    T       T    T    T       T       T    T      F         F        F      F           F
-NUMERIC     T     T    T       T    T    T       T       T    T      F         F        F      F           F
-DECIMAL     T     T    T       T    T    T       T       T    T      F         F        F      F           F
-BITx        T     T    T       T    T    T       T       T    T      F         F        F      F           F
-MONEYx      T     T    T       T    T    T       T       T    T      F         F        F      F           F
-DATETIMEx   T     T    T       F    F    F       F       F    F      T         F        F      F           F
-BOUNDARY    T     T    F       F    F    F       F       F    F      F         T        F      F           F
-UNIQUE      T     T    T       F    F    F       F       F    F      F         F        T      F           F
-SENSITIVITY t     t    F       F    F    F       F       F    F      F         F        F      t           F
+CHARx       T     T    T       T    T    T       T       T    T      T         T        T      T           F
+TEXT        T     T    T       T    T    T       T       T    T      T         T        T      T           F
+BINARYx     T     T    T       T    T    F       F       F    T      F         F        F      T           F
+INTx        T     T    T       T    T    T       T       T    T      F         F        F      T           F
+FLTx        T     T    T       T    T    T       T       T    T      F         F        F      T           F
+NUMERIC     T     T    T       T    T    T       T       T    T      F         F        F      T           F
+DECIMAL     T     T    T       T    T    T       T       T    T      F         F        F      T           F
+BITx        T     T    T       T    T    T       T       T    T      F         F        F      T           F
+MONEYx      T     T    T       T    T    T       T       T    T      F         F        F      T           F
+DATETIMEx   T     T    T       F    F    F       F       F    F      T         F        F      T           F
+BOUNDARY    T     T    F       F    F    F       F       F    F      F         T        F      T           F
+UNIQUE      T     T    T       F    F    F       F       F    F      F         F        T      T           F
+SENSITIVITY T     T    T       T    T    T       T       T    T      T         T        T      T           F
 MSTABLE     F     F    F       F    F    F       F       F    F      F         F        F      F           T
diff --git a/src/tds/unittests/convert.c b/src/tds/unittests/convert.c
index 6e8482706d..4e8533b09a 100644
--- a/src/tds/unittests/convert.c
+++ b/src/tds/unittests/convert.c
@@ -38,6 +38,7 @@ free_convert(int type, CONV_RESULT *cr)
 {
 	switch (type) {
 	case SYBCHAR: case SYBVARCHAR: case SYBTEXT: case XSYBCHAR: case XSYBVARCHAR:
+	case SYBNVARCHAR: case SYBNTEXT: case XSYBNCHAR: case XSYBNVARCHAR:
 	case SYBBINARY: case SYBVARBINARY: case SYBIMAGE: case XSYBBINARY: case XSYBVARBINARY:
 	case SYBLONGBINARY:
 		free(cr->c);
@@ -157,10 +158,18 @@ main(int argc, char **argv)
 		case XSYBVARBINARY:
 		case XSYBCHAR:
 		case XSYBVARCHAR:
+		case SYBNTEXT:
+		case SYBNVARCHAR:
+		case XSYBNCHAR:
+		case XSYBNVARCHAR:
 			switch (desttype) {
 			case SYBCHAR:
 			case SYBVARCHAR:
 			case SYBTEXT:
+			case SYBNTEXT:
+			case SYBNVARCHAR:
+			case XSYBNCHAR:
+			case XSYBNVARCHAR:
 			case SYBDATETIME:
 			case SYBDATETIME4:
 				src = "Jan  1, 1999";