diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..f22db49
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,76 @@
+# idb-connector changelog
+
+## 1.1.5
+
+- Refined docs and trace for scrollable cursor
+- Added a new API stmt.getStmtDiag() as alias of stmt.stmtError()
+- Added CHANGLOG.md
+
+## 1.1.4
+
+- Added test cases for the callback in dbconn.conn()
+- Updated examples with ES6 syntax
+- Required dep "node-pre-gyp" 0.11.0 and above
+
+## 1.1.3
+
+- Fixed the NAPI callback error in DbConn::Conn()
+- Ported and refined the API manual from "developerWorks"
+
+## 1.1.2
+
+- Removed "node-gyp" from dependency list
+- Exposed data types symbols for params binding
+
+## 1.1.1
+
+- Supported fetching result set from stored procedures
+
+## 1.1.0
+
+- Swithed to N-API
+- Added Blob/Binary support and corresponding docs
+- Refined test cases and trace
+
+## 1.0.13
+
+- Supported pre-compiled binary downloading
+- Fixed a memory leak issue
+
+## 1.0.12
+
+- Fixed the truncate issue for big numbers
+
+## 1.0.11
+
+- Supported Node.js v10.x
+
+## 1.0.10
+
+- Refined the code for fetching results and binding params
+- Fixed a string param binding issue
+
+## 1.0.9
+
+- Fixed a statement executing issue
+- Fixed a output param buffer size issue
+
+## 1.0.8
+
+- Added a new API stmt.reset()
+- Fixed a param binding issue
+
+## 1.0.7
+
+- Added support for BINARY SQL data
+- Fixed the 'in/out' param missing issue
+
+## 1.0.6
+
+- Used accurate column width to save memory usage
+- Supported dynamic column width
+
+## 1.0.5
+
+- Provided pre-compiled binary for npm
+- Renamed to idb-connector
\ No newline at end of file
diff --git a/package.json b/package.json
index 7b8f49b..189f232 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "idb-connector",
-  "version": "1.1.4",
+  "version": "1.1.5",
   "description": "A Node.js DB2 driver for IBM i",
   "main": "lib/db2a.js",
   "directories": {
diff --git a/src/db2ia/dbstmt.cc b/src/db2ia/dbstmt.cc
index 2c9f271..32b75d7 100644
--- a/src/db2ia/dbstmt.cc
+++ b/src/db2ia/dbstmt.cc
@@ -1924,14 +1924,14 @@ int DbStmt::populateColumnDescriptions(Napi::Env env) {
         case SQL_WCHAR :
         case SQL_WVARCHAR :
         {
-          maxColLen = dbColumn[i].colPrecise << 2;
+          maxColLen = dbColumn[i].colPrecise * 4 + 1;
           rowData[i] = (SQLCHAR*)calloc(maxColLen, sizeof(SQLCHAR));
           sqlReturnCode = SQLBindCol(stmth, i + 1, SQL_C_CHAR, (SQLPOINTER)rowData[i], maxColLen, &dbColumn[i].rlength);
         }
         break;
-        default :
+        default : // SQL_CHAR / SQL_VARCHAR
         {
-          maxColLen = dbColumn[i].colPrecise + 1;
+          maxColLen = dbColumn[i].colPrecise * 4 + 1;
           rowData[i] = (SQLCHAR*)calloc(maxColLen, sizeof(SQLCHAR));
           sqlReturnCode = SQLBindCol(stmth, i + 1, SQL_C_CHAR, (SQLPOINTER)rowData[i], maxColLen, &dbColumn[i].rlength);
         }