diff --git a/source/shared/core_conn.cpp b/source/shared/core_conn.cpp
index 3d195fe9c..527143557 100644
--- a/source/shared/core_conn.cpp
+++ b/source/shared/core_conn.cpp
@@ -386,7 +386,7 @@ SQLRETURN core_odbc_connect( _Inout_ sqlsrv_conn* conn, _Inout_ std::string& con
 
     // We only support UTF-8 encoding for connection string.
     // Convert our UTF-8 connection string to UTF-16 before connecting with SQLDriverConnnectW
-    wconn_string = utf16_string_from_mbcs_string( SQLSRV_ENCODING_UTF8, conn_str.c_str(), static_cast<unsigned int>( conn_str.length() ), &wconn_len );
+    wconn_string = utf16_string_from_mbcs_string( SQLSRV_ENCODING_UTF8, conn_str.c_str(), static_cast<unsigned int>( conn_str.length() ), &wconn_len, true );
 
     CHECK_CUSTOM_ERROR( wconn_string == 0, conn, SQLSRV_ERROR_CONNECT_STRING_ENCODING_TRANSLATE, get_last_error_message())
     {
diff --git a/source/shared/core_sqlsrv.h b/source/shared/core_sqlsrv.h
index b7a8c3921..c6a0eb97a 100644
--- a/source/shared/core_sqlsrv.h
+++ b/source/shared/core_sqlsrv.h
@@ -1808,7 +1808,7 @@ struct sqlsrv_buffered_result_set : public sqlsrv_result_set {
 bool convert_string_from_utf16_inplace( _In_ SQLSRV_ENCODING encoding, _Inout_updates_z_(len) char** string, _Inout_ SQLLEN& len);
 bool validate_string( _In_ char* string, _In_ SQLLEN& len);
 bool convert_string_from_utf16( _In_ SQLSRV_ENCODING encoding, _In_reads_bytes_(cchInLen) const SQLWCHAR* inString, _In_ SQLINTEGER cchInLen, _Inout_updates_bytes_(cchOutLen) char** outString, _Out_ SQLLEN& cchOutLen );
-SQLWCHAR* utf16_string_from_mbcs_string( _In_ SQLSRV_ENCODING php_encoding, _In_reads_bytes_(mbcs_len) const char* mbcs_string, _In_ unsigned int mbcs_len, _Out_ unsigned int* utf16_len );
+SQLWCHAR* utf16_string_from_mbcs_string( _In_ SQLSRV_ENCODING php_encoding, _In_reads_bytes_(mbcs_len) const char* mbcs_string, _In_ unsigned int mbcs_len, _Out_ unsigned int* utf16_len, bool use_strict_conversion = false );
 
 //*********************************************************************************************************************************
 // Error handling routines and Predefined Errors
diff --git a/source/shared/core_util.cpp b/source/shared/core_util.cpp
index 8fea03358..e5427f97a 100644
--- a/source/shared/core_util.cpp
+++ b/source/shared/core_util.cpp
@@ -34,7 +34,7 @@ char last_err_msg[2048] = {'\0'};  // 2k to hold the error messages
 unsigned int convert_string_from_default_encoding( _In_ unsigned int php_encoding, _In_reads_bytes_(mbcs_len) char const* mbcs_in_string,
                                                    _In_ unsigned int mbcs_len, 
                                                    _Out_writes_(utf16_len) __transfer( mbcs_in_string ) SQLWCHAR* utf16_out_string,
-                                                   _In_ unsigned int utf16_len );
+                                                   _In_ unsigned int utf16_len, bool use_strict_conversion = false );
 }
 
 // SQLSTATE for all internal errors 
@@ -172,11 +172,11 @@ bool convert_string_from_utf16( _In_ SQLSRV_ENCODING encoding, _In_reads_bytes_(
 // allocation of the destination string.  An empty string passed in returns
 // failure since it's a failure case for convert_string_from_default_encoding.
 SQLWCHAR* utf16_string_from_mbcs_string( _In_ SQLSRV_ENCODING php_encoding, _In_reads_bytes_(mbcs_len) const char* mbcs_string, _In_ unsigned int mbcs_len,
-                                        _Out_ unsigned int* utf16_len )
+                                        _Out_ unsigned int* utf16_len, bool use_strict_conversion )
 {
     *utf16_len = (mbcs_len + 1);
     SQLWCHAR* utf16_string = reinterpret_cast<SQLWCHAR*>( sqlsrv_malloc( *utf16_len * sizeof( SQLWCHAR )));
-    *utf16_len = convert_string_from_default_encoding( php_encoding, mbcs_string, mbcs_len, utf16_string, *utf16_len );
+    *utf16_len = convert_string_from_default_encoding( php_encoding, mbcs_string, mbcs_len, utf16_string, *utf16_len, use_strict_conversion );
 
     if( *utf16_len == 0 ) {
         // we preserve the error and reset it because sqlsrv_free resets the last error
@@ -384,7 +384,7 @@ namespace {
 // to convert.
 unsigned int convert_string_from_default_encoding( _In_ unsigned int php_encoding, _In_reads_bytes_(mbcs_len) char const* mbcs_in_string,
                                                    _In_ unsigned int mbcs_len, _Out_writes_(utf16_len) __transfer( mbcs_in_string ) SQLWCHAR* utf16_out_string,
-                                                   _In_ unsigned int utf16_len )
+                                                   _In_ unsigned int utf16_len, bool use_strict_conversion )
 {
     unsigned int win_encoding = CP_ACP;
     switch( php_encoding ) {
@@ -399,8 +399,14 @@ unsigned int convert_string_from_default_encoding( _In_ unsigned int php_encodin
             win_encoding = php_encoding;
             break;
     }
-#ifndef _WIN32 
-    unsigned int required_len = SystemLocale::ToUtf16( win_encoding, mbcs_in_string, mbcs_len, utf16_out_string, utf16_len );
+#ifndef _WIN32
+    unsigned int required_len;
+    if (use_strict_conversion) {
+        required_len = SystemLocale::ToUtf16Strict( win_encoding, mbcs_in_string, mbcs_len, utf16_out_string, utf16_len );
+    }
+    else {
+        required_len = SystemLocale::ToUtf16( win_encoding, mbcs_in_string, mbcs_len, utf16_out_string, utf16_len );
+    }
 #else
     unsigned int required_len = MultiByteToWideChar( win_encoding, MB_ERR_INVALID_CHARS, mbcs_in_string, mbcs_len, utf16_out_string, utf16_len );
 #endif // !_Win32
@@ -610,4 +616,4 @@ namespace data_classification {
 
         columns_sensitivity.clear();
     }
-} // namespace data_classification
\ No newline at end of file
+} // namespace data_classification
diff --git a/source/sqlsrv/php_sqlsrv_int.h b/source/sqlsrv/php_sqlsrv_int.h
index c294f465b..bd555fe10 100644
--- a/source/sqlsrv/php_sqlsrv_int.h
+++ b/source/sqlsrv/php_sqlsrv_int.h
@@ -214,12 +214,12 @@ bool ss_error_handler( _Inout_ sqlsrv_context& ctx, _In_ unsigned int sqlsrv_err
 // returned in utf16_out_string.
 unsigned int convert_string_from_default_encoding( _In_ unsigned int php_encoding, _In_reads_bytes_(mbcs_len) char const* mbcs_in_string,
                                                    _In_ unsigned int mbcs_len, _Out_writes_(utf16_len) __transfer(mbcs_in_string) wchar_t* utf16_out_string,
-                                                   _In_ unsigned int utf16_len );
+                                                   _In_ unsigned int utf16_len, bool use_strict_conversion = false );
 // create a wide char string from the passed in mbcs string.  NULL is returned if the string
 // could not be created.  No error is posted by this function.  utf16_len is the number of
 // wchar_t characters, not the number of bytes.
 SQLWCHAR* utf16_string_from_mbcs_string( _In_ unsigned int php_encoding, _In_reads_bytes_(mbcs_len) const char* mbcs_string,
-                                        _In_ unsigned int mbcs_len, _Out_ unsigned int* utf16_len );
+                                        _In_ unsigned int mbcs_len, _Out_ unsigned int* utf16_len, bool use_strict_conversion = false );
 
 // *** internal error macros and functions ***
 bool handle_error( sqlsrv_context const* ctx, int log_subsystem, const char* function, 
diff --git a/test/functional/pdo_sqlsrv/pdo_construct_attr_errors.phpt b/test/functional/pdo_sqlsrv/pdo_construct_attr_errors.phpt
index a31974d94..7b0f101a6 100644
--- a/test/functional/pdo_sqlsrv/pdo_construct_attr_errors.phpt
+++ b/test/functional/pdo_sqlsrv/pdo_construct_attr_errors.phpt
@@ -38,7 +38,7 @@ function invalidServer()
         echo "Should have failed to connect to invalid server.\n";
     }  catch (PDOException $e) {
         $error1 = '*Login timeout expired';
-        $error2 = '*An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page*';
+        $error2 = '*An error occurred translating the connection string to UTF-16: *';
         if (fnmatch($error1, $e->getMessage()) || fnmatch($error2, $e->getMessage())) {
             ;   // matched at least one of the expected error messages 
         } else {
@@ -102,7 +102,7 @@ function invalidPassword()
     $options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
     
     // Possible errors
-    $error = "*An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page.*";
+    $error = "*An error occurred translating the connection string to UTF-16: *";
     $error1 = "*Login failed for user \'*\'.";
     $error2 = "*Login timeout expired*";
 
diff --git a/test/functional/sqlsrv/sqlsrv_connStr.phpt b/test/functional/sqlsrv/sqlsrv_connStr.phpt
index 144ceb94a..7c92bd997 100644
--- a/test/functional/sqlsrv/sqlsrv_connStr.phpt
+++ b/test/functional/sqlsrv/sqlsrv_connStr.phpt
@@ -1,11 +1,18 @@
 --TEST--
 UTF-8 connection strings
 --SKIPIF--
-<?php require('skipif_unix.inc'); ?>
+<?php require('skipif.inc'); ?>
 --FILE--
 <?php
 
 require_once('MsSetup.inc');
+
+// Expected errors
+$gibberishEncoding = array('IMSSP', '-48', "The encoding 'gibberish' is not a supported encoding for the CharacterSet connection option.");   
+$binaryEncoding = array('IMSSP', '-48', "The encoding 'binary' is not a supported encoding for the CharacterSet connection option.");   
+$utf16Error = array('IMSSP', '-47', "An error occurred translating the connection string to UTF-16: *");
+$userLoginFailed = array('28000', '18456', "*Login failed for user *");
+
 function connect($options=array())
 {
     global $server, $uid, $pwd, $databaseName;
@@ -22,6 +29,17 @@ function connect($options=array())
     return sqlsrv_connect($server, $options);
 }
 
+function checkErrors($expectedError)
+{
+    // On Windows one call returns two identical errors, so just take the first element
+    $error = sqlsrv_errors()[0];
+    if (!fnmatch($expectedError[0], $error[0]) || 
+        !fnmatch($expectedError[1], $error[1]) || 
+        !fnmatch($expectedError[2], $error[2])) {
+        fatalError("Errors do not match!\n");
+    }
+}
+
 sqlsrv_configure('WarningsReturnAsErrors', 0);
 sqlsrv_configure('LogSeverity', SQLSRV_LOG_SEVERITY_ALL);
 
@@ -30,13 +48,13 @@ $c = connect(array( 'CharacterSet' => 'gibberish' ));
 if ($c !== false) {
     fatalError("Should have errored on an invalid encoding.");
 }
-print_r(sqlsrv_errors());
+checkErrors($gibberishEncoding);
 
 $c = connect(array( 'CharacterSet' => SQLSRV_ENC_BINARY ));
 if ($c !== false) {
     fatalError("Should have errored on an invalid encoding.");
 }
-print_r(sqlsrv_errors());
+checkErrors($binaryEncoding);
 
 $c = connect(array( 'CharacterSet' => SQLSRV_ENC_CHAR ));
 if ($c === false) {
@@ -50,7 +68,7 @@ $c = sqlsrv_connect($server_invalid, array( 'Database' => 'test', 'CharacterSet'
 if ($c !== false) {
     fatalError("sqlsrv_connect(1) should have failed");
 }
-print_r(sqlsrv_errors());
+checkErrors($utf16Error);
 
 // APP has a UTF-8 name
 $c = connect(array(
@@ -67,7 +85,7 @@ $c = connect(array(
 if ($c !== false) {
     fatalError("sqlsrv_connect(3) should have failed");
 }
-print_r(sqlsrv_errors());
+checkErrors($userLoginFailed);
 
 // invalid UTF-8 in the pwd
 $c = connect(array(
@@ -77,89 +95,10 @@ $c = connect(array(
 if ($c !== false) {
     fatalError("sqlsrv_connect(4) should have failed");
 }
-print_r(sqlsrv_errors());
+checkErrors($utf16Error);
 
 echo "Test succeeded.\n";
 
 ?>
---EXPECTF--
-Array
-(
-    [0] => Array
-        (
-            [0] => IMSSP
-            [SQLSTATE] => IMSSP
-            [1] => -48
-            [code] => -48
-            [2] => The encoding 'gibberish' is not a supported encoding for the CharacterSet connection option.
-            [message] => The encoding 'gibberish' is not a supported encoding for the CharacterSet connection option.
-        )
-
-)
-Array
-(
-    [0] => Array
-        (
-            [0] => IMSSP
-            [SQLSTATE] => IMSSP
-            [1] => -48
-            [code] => -48
-            [2] => The encoding 'binary' is not a supported encoding for the CharacterSet connection option.
-            [message] => The encoding 'binary' is not a supported encoding for the CharacterSet connection option.
-        )
-
-)
-Array
-(
-    [0] => Array
-        (
-            [0] => IMSSP
-            [SQLSTATE] => IMSSP
-            [1] => -47
-            [code] => -47
-            [2] => An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page.
-
-            [message] => An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page.
-
-        )
-
-)
-Array
-(
-    [0] => Array
-        (
-            [0] => 28000
-            [SQLSTATE] => 28000
-            [1] => 18456
-            [code] => 18456
-            [2] => %SLogin failed for user '%s'.
-            [message] => %SLogin failed for user '%s'.
-        )
-
-    [1] => Array
-        (
-            [0] => 28000
-            [SQLSTATE] => 28000
-            [1] => 18456
-            [code] => 18456
-            [2] => %SLogin failed for user '%s'.
-            [message] => %SLogin failed for user '%s'.
-        )
-
-)
-Array
-(
-    [0] => Array
-        (
-            [0] => IMSSP
-            [SQLSTATE] => IMSSP
-            [1] => -47
-            [code] => -47
-            [2] => An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page.
-
-            [message] => An error occurred translating the connection string to UTF-16: No mapping for the Unicode character exists in the target multi-byte code page.
-
-        )
-
-)
+--EXPECT--
 Test succeeded.