diff --git a/include/xlnt/utils/utf8string.hpp b/include/xlnt/utils/utf8string.hpp
index f4f8ee59..f83e01ba 100644
--- a/include/xlnt/utils/utf8string.hpp
+++ b/include/xlnt/utils/utf8string.hpp
@@ -36,8 +36,8 @@ class XLNT_CLASS utf8string
 public:
     static utf8string from_utf8(const std::string &s);
     static utf8string from_latin1(const std::string &s);
-    static utf8string from_utf16(const std::string &s);
-    static utf8string from_utf32(const std::string &s);
+    static utf8string from_utf16(const std::vector<std::uint16_t> &s);
+    static utf8string from_utf32(const std::vector<std::uint32_t> &s);
 
     static bool is_valid(const std::string &s);
 
diff --git a/source/cell/cell.cpp b/source/cell/cell.cpp
index eb204550..e3a759d1 100644
--- a/source/cell/cell.cpp
+++ b/source/cell/cell.cpp
@@ -141,53 +141,7 @@ std::string cell::check_string(const std::string &to_check)
     {
         return s;
     }
-
-    auto wb_encoding = get_workbook().get_encoding();
-
-    //XXX: use utfcpp for this!
-    switch(wb_encoding)
-    {
-    case encoding::latin1: break; // all bytes are valid in latin1
-    case encoding::ascii:
-        for (char c : s)
-        {
-            if (c < 0)
-            {
-                throw xlnt::unicode_decode_error(c);
-            }
-        }
-        break;
-    case encoding::utf8:
-    {
-	if(!utf8string::is_valid(s))
-        {
-            throw xlnt::unicode_decode_error('0');
-        } 
-        break;
-    }
-    case encoding::utf16:
-    {
-	if(!utf8string::from_utf16(s).is_valid())
-        {
-            throw xlnt::unicode_decode_error('0');
-        } 
-        break;
-    }
-    case encoding::utf32:
-    {
-	if(!utf8string::from_utf32(s).is_valid())
-        {
-            throw xlnt::unicode_decode_error('0');
-        } 
-        break;
-    }
-    default:
-        // other encodings not supported yet
-        break;
-    } // switch(wb_encoding)
-
-    // check encoding?
-    if (s.size() > 32767)
+    else if (s.size() > 32767)
     {
         s = s.substr(0, 32767); // max string length in Excel
     }
diff --git a/source/cell/tests/test_cell.hpp b/source/cell/tests/test_cell.hpp
index 4cd65ce7..9d83cf1e 100644
--- a/source/cell/tests/test_cell.hpp
+++ b/source/cell/tests/test_cell.hpp
@@ -53,6 +53,9 @@ public:
 		cell.set_value("03:40:16");
         TS_ASSERT(cell.get_value<xlnt::time>() == xlnt::time(3, 40, 16));
 
+		cell.set_value("03:");
+        TS_ASSERT_EQUALS(cell.get_value<std::string>(), "03:");
+
 		cell.set_value("03:40");
         TS_ASSERT(cell.get_value<xlnt::time>() == xlnt::time(3, 40));
 
@@ -322,15 +325,7 @@ public:
         auto test_string = "Compound Value (" + std::string(1, pound) + ")";
         return test_string;
     }
-    
-    void test_bad_encoding()
-    {
-        auto ws = wb.create_sheet();
-        auto cell = ws[xlnt::cell_reference("A1")];
-        TS_ASSERT_THROWS(cell.check_string(make_latin1_string()), xlnt::unicode_decode_error);
-        TS_ASSERT_THROWS(cell.set_value(make_latin1_string()), xlnt::unicode_decode_error);
-    }
-    
+
     void test_good_encoding()
     {
         xlnt::workbook latin1_wb(xlnt::encoding::latin1);
diff --git a/source/utils/tests/test_utf8string.hpp b/source/utils/tests/test_utf8string.hpp
index 0e847bad..e1d82b47 100644
--- a/source/utils/tests/test_utf8string.hpp
+++ b/source/utils/tests/test_utf8string.hpp
@@ -24,13 +24,13 @@ public:
     
     void test_utf16()
     {
-        auto utf16_valid = xlnt::utf8string::from_utf16("abc");
+        auto utf16_valid = xlnt::utf8string::from_utf16({ 'a', 'b', 'c' });
         TS_ASSERT(utf16_valid.is_valid());
     }
     
     void test_utf32()
     {
-        auto utf32_valid = xlnt::utf8string::from_utf32("abc");
+        auto utf32_valid = xlnt::utf8string::from_utf32({ 'a', 'b', 'c' });
         TS_ASSERT(utf32_valid.is_valid());
     }
 };
diff --git a/source/utils/utf8string.cpp b/source/utils/utf8string.cpp
index 8e4bd61b..1b089880 100644
--- a/source/utils/utf8string.cpp
+++ b/source/utils/utf8string.cpp
@@ -21,6 +21,7 @@
 // @license: http://www.opensource.org/licenses/mit-license.php
 // @author: see AUTHORS file
 #include <xlnt/utils/utf8string.hpp>
+#include <xlnt/utils/unicode_decode_error.hpp>
 
 namespace xlnt {
 
@@ -40,7 +41,7 @@ utf8string utf8string::from_latin1(const std::string &s)
     return result;
 }
 
-utf8string utf8string::from_utf16(const std::string &s)
+utf8string utf8string::from_utf16(const std::vector<std::uint16_t> &s)
 {
     utf8string result;
     utf8::utf16to8(s.begin(), s.end(), std::back_inserter(result.bytes_));
@@ -48,7 +49,7 @@ utf8string utf8string::from_utf16(const std::string &s)
     return result;
 }
 
-utf8string utf8string::from_utf32(const std::string &s)
+utf8string utf8string::from_utf32(const std::vector<std::uint32_t> &s)
 {
     utf8string result;
     utf8::utf32to8(s.begin(), s.end(), std::back_inserter(result.bytes_));