diff --git a/source/mijin/util/os.cpp b/source/mijin/util/os.cpp
index 9d2d98a..1d7b7ce 100644
--- a/source/mijin/util/os.cpp
+++ b/source/mijin/util/os.cpp
@@ -2,6 +2,7 @@
 #include "os.hpp"
 
 #include <filesystem>
+#include "../debug/assert.hpp"
 
 #if MIJIN_TARGET_OS == MIJIN_OS_LINUX
     #include <mutex>
@@ -106,7 +107,7 @@ std::string getExecutablePath() MIJIN_NOEXCEPT
 #elif MIJIN_TARGET_OS == MIJIN_OS_WINDOWS
     // TODO: this is completely untested
     std::array<char, 1024> buffer;
-    if (FAILED(GetModuleFileNameA(nullptr, buffer.data(), buffer.size())))
+    if (FAILED(GetModuleFileNameA(nullptr, buffer.data(), static_cast<DWORD>(buffer.size()))))
     {
         std::vector<char> buffer2;
         buffer2.resize(1024);
@@ -119,7 +120,7 @@ std::string getExecutablePath() MIJIN_NOEXCEPT
             }
             buffer2.resize(buffer2.size() + 1024);
         }
-        while (FAILED(GetModuleFileNameA(nullptr, buffer.data(), buffer.size())));
+        while (FAILED(GetModuleFileNameA(nullptr, buffer.data(), static_cast<DWORD>(buffer.size()))));
         return buffer2.data();
     }
     return buffer.data();