diff --git a/CMakeLists.txt b/CMakeLists.txt
index a28abbc7b..ed8919ba4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -211,7 +211,7 @@ add_library(PKWare STATIC
   3rdParty/PKWare/explode.cpp
   3rdParty/PKWare/implode.cpp)
 
-set(devilutionx_SRCS
+set(devilutionx_SRCS
   Source/appfat.cpp
   Source/automap.cpp
   Source/capture.cpp
@@ -296,6 +296,7 @@ set(devilutionx_SRCS
   Source/controls/touch.cpp
   Source/utils/console.cpp
   Source/utils/display.cpp
+  Source/utils/file_util.cpp
   Source/utils/paths.cpp
   Source/utils/soundsample.cpp
   Source/utils/thread.cpp
@@ -359,7 +360,7 @@ if(SWITCH)
     Source/platform/switch/docking.cpp)
   set(BIN_TARGET devilutionx.elf)
 endif()
-
+
 if(VITA)
   list(APPEND devilutionx_SRCS
     Source/platform/vita/keyboard.cpp)
diff --git a/Source/utils/file_util.cpp b/Source/utils/file_util.cpp
new file mode 100644
index 000000000..7245a9c01
--- /dev/null
+++ b/Source/utils/file_util.cpp
@@ -0,0 +1,113 @@
+#include "utils/file_util.h"
+
+#include <algorithm>
+#include <string>
+
+#include <SDL.h>
+
+#ifdef USE_SDL1
+#include "utils/sdl2_to_1_2_backports.h"
+#endif
+
+#if defined(_WIN64) || defined(_WIN32)
+// Suppress definitions of `min` and `max` macros by <windows.h>:
+#define NOMINMAX 1
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
+#if _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
+#include <unistd.h>
+#include <sys/stat.h>
+#else
+#include <cstdio>
+#endif
+
+namespace devilution {
+
+bool FileExists(const char *path)
+{
+#if _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
+	return ::access(path, F_OK) == 0;
+#else
+	FILE *file = std::fopen(path, "rb");
+	if (file == NULL)
+		return false;
+	std::fclose(file);
+	return true;
+#endif
+}
+
+bool GetFileSize(const char *path, std::uintmax_t *size)
+{
+#if defined(_WIN64) || defined(_WIN32)
+	WIN32_FILE_ATTRIBUTE_DATA attr;
+	int path_utf16_size = MultiByteToWideChar(CP_UTF8, 0, path, -1, NULL, 0);
+	wchar_t *path_utf16 = new wchar_t[path_utf16_size];
+	if (MultiByteToWideChar(CP_UTF8, 0, path, -1, path_utf16, path_utf16_size) != path_utf16_size) {
+		delete[] path_utf16;
+		return false;
+	}
+	if (!GetFileAttributesExW(path_utf16, GetFileExInfoStandard, &attr)) {
+		delete[] path_utf16;
+		return false;
+	}
+	delete[] path_utf16;
+	*size = (attr.nFileSizeHigh) << (sizeof(attr.nFileSizeHigh) * 8) | attr.nFileSizeLow;
+	return true;
+#else
+	struct ::stat stat_result;
+	if (::stat(path, &stat_result) == -1)
+		return false;
+	*size = static_cast<uintmax_t>(stat_result.st_size);
+	return true;
+#endif
+}
+
+bool ResizeFile(const char *path, std::uintmax_t size)
+{
+#if defined(_WIN64) || defined(_WIN32)
+	LARGE_INTEGER lisize;
+	lisize.QuadPart = static_cast<LONGLONG>(size);
+	if (lisize.QuadPart < 0) {
+		return false;
+	}
+	int path_utf16_size = MultiByteToWideChar(CP_UTF8, 0, path, -1, NULL, 0);
+	wchar_t *path_utf16 = new wchar_t[path_utf16_size];
+	if (MultiByteToWideChar(CP_UTF8, 0, path, -1, path_utf16, path_utf16_size) != path_utf16_size) {
+		delete[] path_utf16;
+		return false;
+	}
+	HANDLE file = ::CreateFileW(path_utf16, GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
+	delete[] path_utf16;
+	if (file == INVALID_HANDLE_VALUE) {
+		return false;
+	} else if (::SetFilePointerEx(file, lisize, NULL, FILE_BEGIN) == 0 || ::SetEndOfFile(file) == 0) {
+		::CloseHandle(file);
+		return false;
+	}
+	::CloseHandle(file);
+	return true;
+#elif _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
+	return ::truncate(path, static_cast<off_t>(size)) == 0;
+#else
+	static_assert(false, "truncate not implemented for the current platform");
+#endif
+}
+
+void RemoveFile(const char *lpFileName)
+{
+	std::string name = lpFileName;
+	std::replace(name.begin(), name.end(), '\\', '/');
+	FILE *f = fopen(name.c_str(), "r+");
+	if (f) {
+		fclose(f);
+		remove(name.c_str());
+		f = NULL;
+		SDL_Log("Removed file: %s", name.c_str());
+	} else {
+		SDL_Log("Failed to remove file: %s", name.c_str());
+	}
+}
+
+} // namespace devilution
diff --git a/Source/utils/file_util.h b/Source/utils/file_util.h
index 879db38a9..61b3a9320 100644
--- a/Source/utils/file_util.h
+++ b/Source/utils/file_util.h
@@ -1,114 +1,11 @@
 #pragma once
 
-#include <algorithm>
-#include <string>
 #include <cstdint>
-
-#include <SDL.h>
-
-#ifdef USE_SDL1
-#include "utils/sdl2_to_1_2_backports.h"
-#endif
-
-#if defined(_WIN64) || defined(_WIN32)
-// Suppress definitions of `min` and `max` macros by <windows.h>:
-#define NOMINMAX 1
-#define WIN32_LEAN_AND_MEAN
-#include <windows.h>
-#endif
-
-#if _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
-#include <unistd.h>
-#include <sys/stat.h>
-#else
-#include <cstdio>
-#endif
-
 namespace devilution {
 
-inline bool FileExists(const char *path)
-{
-#if _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
-	return ::access(path, F_OK) == 0;
-#else
-	FILE *file = std::fopen(path, "rb");
-	if (file == NULL)
-		return false;
-	std::fclose(file);
-	return true;
-#endif
-}
-
-inline bool GetFileSize(const char *path, std::uintmax_t *size)
-{
-#if defined(_WIN64) || defined(_WIN32)
-	WIN32_FILE_ATTRIBUTE_DATA attr;
-	int path_utf16_size = MultiByteToWideChar(CP_UTF8, 0, path, -1, NULL, 0);
-	wchar_t *path_utf16 = new wchar_t[path_utf16_size];
-	if (MultiByteToWideChar(CP_UTF8, 0, path, -1, path_utf16, path_utf16_size) != path_utf16_size) {
-		delete[] path_utf16;
-		return false;
-	}
-	if (!GetFileAttributesExW(path_utf16, GetFileExInfoStandard, &attr)) {
-		delete[] path_utf16;
-		return false;
-	}
-	delete[] path_utf16;
-	*size = (attr.nFileSizeHigh) << (sizeof(attr.nFileSizeHigh) * 8) | attr.nFileSizeLow;
-	return true;
-#else
-	struct ::stat stat_result;
-	if (::stat(path, &stat_result) == -1)
-		return false;
-	*size = static_cast<uintmax_t>(stat_result.st_size);
-	return true;
-#endif
-}
-
-inline bool ResizeFile(const char *path, std::uintmax_t size)
-{
-#if defined(_WIN64) || defined(_WIN32)
-	LARGE_INTEGER lisize;
-	lisize.QuadPart = static_cast<LONGLONG>(size);
-	if (lisize.QuadPart < 0) {
-		return false;
-	}
-	int path_utf16_size = MultiByteToWideChar(CP_UTF8, 0, path, -1, NULL, 0);
-	wchar_t *path_utf16 = new wchar_t[path_utf16_size];
-	if (MultiByteToWideChar(CP_UTF8, 0, path, -1, path_utf16, path_utf16_size) != path_utf16_size) {
-		delete[] path_utf16;
-		return false;
-	}
-	HANDLE file = ::CreateFileW(path_utf16, GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
-	delete[] path_utf16;
-	if (file == INVALID_HANDLE_VALUE) {
-		return false;
-	} else if (::SetFilePointerEx(file, lisize, NULL, FILE_BEGIN) == 0 || ::SetEndOfFile(file) == 0) {
-		::CloseHandle(file);
-		return false;
-	}
-	::CloseHandle(file);
-	return true;
-#elif _POSIX_C_SOURCE >= 200112L || defined(_BSD_SOURCE) || defined(__APPLE__)
-	return ::truncate(path, static_cast<off_t>(size)) == 0;
-#else
-	static_assert(false, "truncate not implemented for the current platform");
-#endif
-}
-
-inline void RemoveFile(const char *lpFileName)
-{
-	std::string name = lpFileName;
-	std::replace(name.begin(), name.end(), '\\', '/');
-	FILE *f = fopen(name.c_str(), "r+");
-	if (f) {
-		fclose(f);
-		remove(name.c_str());
-		f = NULL;
-		SDL_Log("Removed file: %s", name.c_str());
-	} else {
-		SDL_Log("Failed to remove file: %s", name.c_str());
-	}
-}
+bool FileExists(const char *path);
+bool GetFileSize(const char *path, std::uintmax_t *size);
+bool ResizeFile(const char *path, std::uintmax_t size);
+void RemoveFile(const char *lpFileName);
 
 } // namespace devilution