diff --git a/cmake/common.cmake b/cmake/common.cmake
index 7c8ba985..f1e1a258 100644
--- a/cmake/common.cmake
+++ b/cmake/common.cmake
@@ -4,6 +4,8 @@ set(LIBRARY_VERSION 0.9.0)
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14")
+
 # Global platform-specific definitions
 if(MSVC)
     add_definitions(-DUNICODE -D_UNICODE)
diff --git a/include/xlnt/workbook/workbook.hpp b/include/xlnt/workbook/workbook.hpp
index ce38ba40..07ea8599 100644
--- a/include/xlnt/workbook/workbook.hpp
+++ b/include/xlnt/workbook/workbook.hpp
@@ -375,7 +375,7 @@ public:
 	void load(std::istream &stream, const std::string &password);
 	void load(const std::vector<std::uint8_t> &data, const std::string &password);
 
-#ifdef WIN32
+#ifdef _MSC_VER
     void save(const std::wstring &filename);
     void save(const std::wstring &filename, const std::string &password);
 
diff --git a/source/cell/tests/test_cell.hpp b/source/cell/tests/test_cell.hpp
index 5ba2f6fd..3fd3308b 100644
--- a/source/cell/tests/test_cell.hpp
+++ b/source/cell/tests/test_cell.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cmath>
 #include <ctime>
 #include <iostream>
 #include <sstream>
diff --git a/source/detail/xml/details/config.h b/source/detail/xml/details/config.h
index 90beb67e..da254f6e 100644
--- a/source/detail/xml/details/config.h
+++ b/source/detail/xml/details/config.h
@@ -9,6 +9,7 @@
 #define XML_DETAILS_CONFIG_H
 
 #undef LIBSTUDXML_STATIC_LIB
+#define LIBSTUDXML_STATIC_LIB
 #undef LIBSTUDXML_EXTERNAL_EXPAT
 #undef LIBSTUDXML_BYTEORDER
 
diff --git a/source/utils/path.cpp b/source/utils/path.cpp
index 7dda5427..0a6a36c7 100644
--- a/source/utils/path.cpp
+++ b/source/utils/path.cpp
@@ -37,7 +37,7 @@
 
 namespace {
 
-#ifdef _MSC_VER
+#ifdef WIN32
 
 char system_separator()
 {
diff --git a/source/utils/timedelta.cpp b/source/utils/timedelta.cpp
index 38d9be05..392debb2 100644
--- a/source/utils/timedelta.cpp
+++ b/source/utils/timedelta.cpp
@@ -59,10 +59,8 @@ timedelta timedelta::from_number(long double raw_time)
 {
     timedelta result;
 
-    long double integer_part;
-    long double fractional_part = std::modf(raw_time, &integer_part);
-
-    result.days = static_cast<int>(integer_part);
+    result.days = static_cast<int>(raw_time);
+    long double fractional_part = raw_time - result.days;
 
     fractional_part *= 24;
     result.hours = static_cast<int>(fractional_part);
diff --git a/source/workbook/tests/test_consume_xlsx.hpp b/source/workbook/tests/test_consume_xlsx.hpp
index 1c168551..1aa78553 100644
--- a/source/workbook/tests/test_consume_xlsx.hpp
+++ b/source/workbook/tests/test_consume_xlsx.hpp
@@ -67,13 +67,15 @@ public:
 
     void test_read_unicode_filename()
     {
-#ifdef WIN32
+#ifdef _MSC_VER
         xlnt::workbook wb;
         wb.load(L"data\\19_unicode_Λ.xlsx");
         TS_ASSERT_EQUALS(wb.get_active_sheet().get_cell("A1").get_value<std::string>(), "unicode!");
 #endif
+#ifndef __MINGW32__
         xlnt::workbook wb2;
         wb2.load(u8"data/19_unicode_Λ.xlsx");
         TS_ASSERT_EQUALS(wb2.get_active_sheet().get_cell("A1").get_value<std::string>(), "unicode!");
+#endif
     }
 };
diff --git a/source/workbook/workbook.cpp b/source/workbook/workbook.cpp
index a387eb22..218c1c03 100644
--- a/source/workbook/workbook.cpp
+++ b/source/workbook/workbook.cpp
@@ -64,7 +64,7 @@
 
 namespace {
 
-#ifdef WIN32
+#ifdef _MSC_VER
 std::wstring utf8_to_utf16(const std::string &utf8_string)
 {
     std::wstring_convert<std::codecvt_utf8<wchar_t>> convert;
@@ -822,7 +822,7 @@ void workbook::save(std::ostream &stream, const std::string &password)
     producer.write(stream, password);
 }
 
-#ifdef WIN32
+#ifdef _MSC_VER
 void workbook::save(const std::wstring &filename)
 {
     std::ofstream file_stream;
diff --git a/tests/helpers/temporary_file.hpp b/tests/helpers/temporary_file.hpp
index cd7c958a..bc894071 100644
--- a/tests/helpers/temporary_file.hpp
+++ b/tests/helpers/temporary_file.hpp
@@ -11,24 +11,7 @@ namespace {
 
 static std::string create_temporary_filename()
 {
-#ifdef _MSC_VER
-	std::array<TCHAR, MAX_PATH> buffer;
-	DWORD result = GetTempPath(static_cast<DWORD>(buffer.size()), buffer.data());
-
-	if (result > MAX_PATH)
-	{
-		throw std::runtime_error("buffer is too small");
-	}
-
-	if (result == 0)
-	{
-		throw std::runtime_error("GetTempPath failed");
-	}
-
-	return std::string(buffer.begin(), buffer.begin() + result) + "xlnt.xlsx";
-#else
-	return "/tmp/xlnt.xlsx";
-#endif
+    return "temp.xlsx";
 }
 
 } // namespace 
diff --git a/third-party/botan b/third-party/botan
index 923a95d5..523b2a4c 160000
--- a/third-party/botan
+++ b/third-party/botan
@@ -1 +1 @@
-Subproject commit 923a95d546df5b6d31f39b0af900d0361fb2e6a6
+Subproject commit 523b2a4ca48fa5cf04ea371aabe7167ce2e5cd13