diff --git a/tests/file_helper.cpp b/tests/file_helper.cpp
index f82e6758..f57ab707 100644
--- a/tests/file_helper.cpp
+++ b/tests/file_helper.cpp
@@ -36,7 +36,7 @@ TEST_CASE("file_helper_size", "[file_helper::size()]]")
         write_with_helper(helper, expected_size);
         REQUIRE(helper.size() == expected_size);
     }
-    REQUIRE(filesize(filename) == expected_size);
+    REQUIRE(get_filesize(filename) == expected_size);
 }
 
 
diff --git a/tests/file_log.cpp b/tests/file_log.cpp
index e728a963..2abd0214 100644
--- a/tests/file_log.cpp
+++ b/tests/file_log.cpp
@@ -52,9 +52,9 @@ TEST_CASE("rotating_file_logger2", "[rotating_logger]]")
         logger->info("Test message {}", i);
 
     logger->flush();
-    REQUIRE(filesize(filename) <= 1024);
+    REQUIRE(get_filesize(filename) <= 1024);
     auto filename1 = basename + ".1.txt";
-    REQUIRE(filesize(filename1) <= 1024);
+    REQUIRE(get_filesize(filename1) <= 1024);
 }
 
 
diff --git a/tests/tests.vcxproj b/tests/tests.vcxproj
index 7272c212..cd8e5a5d 100644
--- a/tests/tests.vcxproj
+++ b/tests/tests.vcxproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project DefaultTargets="Build" ToolsVersion="14.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <ItemGroup Label="ProjectConfigurations">
     <ProjectConfiguration Include="Debug|Win32">
       <Configuration>Debug</Configuration>
@@ -26,26 +26,26 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>true</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
     <ConfigurationType>Application</ConfigurationType>
     <UseDebugLibraries>false</UseDebugLibraries>
-    <PlatformToolset>v120</PlatformToolset>
+    <PlatformToolset>v140</PlatformToolset>
     <WholeProgramOptimization>true</WholeProgramOptimization>
     <CharacterSet>MultiByte</CharacterSet>
   </PropertyGroup>
@@ -126,10 +126,12 @@
     <ClCompile Include="format.cpp" />
     <ClCompile Include="main.cpp" />
     <ClCompile Include="registry.cpp" />
+    <ClCompile Include="utils.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="catch.hpp" />
     <ClInclude Include="includes.h" />
+    <ClInclude Include="utils.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
diff --git a/tests/tests.vcxproj.filters b/tests/tests.vcxproj.filters
index bdadb0bc..8a1a5d6c 100644
--- a/tests/tests.vcxproj.filters
+++ b/tests/tests.vcxproj.filters
@@ -30,6 +30,9 @@
     <ClCompile Include="file_helper.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="utils.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="includes.h">
@@ -38,5 +41,8 @@
     <ClInclude Include="catch.hpp">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="utils.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/tests/utils.cpp b/tests/utils.cpp
index ef6018b6..140465bd 100644
--- a/tests/utils.cpp
+++ b/tests/utils.cpp
@@ -34,7 +34,7 @@ std::size_t count_lines(const std::string& filename)
     return counter;
 }
 
-std::ifstream::pos_type filesize(const std::string& filename)
+std::size_t get_filesize(const std::string& filename)
 {
     std::ifstream ifs(filename, std::ifstream::ate | std::ifstream::binary);
     if (!ifs)
diff --git a/tests/utils.h b/tests/utils.h
index eea5d6c5..1d9b6213 100644
--- a/tests/utils.h
+++ b/tests/utils.h
@@ -11,5 +11,5 @@ std::string file_contents(const std::string& filename);
 
 std::size_t count_lines(const std::string& filename);
 
-std::ifstream::pos_type filesize(const std::string& filename);
+std::size_t get_filesize(const std::string& filename);