diff --git a/source/lib/path_util.cpp b/source/lib/path_util.cpp
index 6ea3b08319..58c44c4327 100644
--- a/source/lib/path_util.cpp
+++ b/source/lib/path_util.cpp
@@ -43,7 +43,7 @@ AT_STARTUP(\
 
 static inline bool is_dir_sep(char c)
 {
-	// note: ideally path strings would only contain '/' or even DIR_SEP.
+	// note: ideally path strings would only contain '/' or even SYS_DIR_SEP.
 	// however, windows-specific code (e.g. the sound driver detection)
 	// uses these routines with '\\' strings. converting them all to
 	// '/' and then back before passing to WinAPI would be annoying.
@@ -241,14 +241,14 @@ LibError path_replace(char* dst, const char* src, const char* remove, const char
 // characters up to the last dir separator, if any).
 const char* path_name_only(const char* path)
 {
-	const char* portable_slash = strrchr(path, '/');
-	const char* platform_slash = strrchr(path, DIR_SEP);
+	const char* slash1 = strrchr(path, '/');
+	const char* slash2 = strrchr(path, '\\');
 	// neither present, it's a filename only
-	if(!portable_slash && !platform_slash)
+	if(!slash1 && !slash2)
 		return path;
 
 	// return name, i.e. component after the last portable or platform slash
-	return MAX(portable_slash, platform_slash)+1;
+	return MAX(slash1, slash2)+1;
 }
 
 
@@ -258,7 +258,7 @@ const char* path_name_only(const char* path)
 const char* path_last_component(const char* path)
 {
 	// ('\0' is end of set string)
-	static const char separators[3] = { DIR_SEP, '/', '\0' };
+	static const char separators[3] = { '/', '\\', '\0' };
 
 	const char* pos = path;
 	const char* last_component = path;
@@ -334,9 +334,9 @@ LibError path_foreach_component(const char* path_org, PathComponentCb cb, void*
 
 		// find end of cur_component
 		char* slash = (char*)strchr(cur_component, '/');
-		// .. try platform-specific separator
+		// .. try other separator
 		if(!slash)
-			slash = (char*)strchr(cur_component, DIR_SEP);
+			slash = (char*)strchr(cur_component, '\\');
 
 		// decide its type and 0-terminate
 		// .. filename (by definition)
@@ -382,7 +382,7 @@ LibError path_foreach_component(const char* path_org, PathComponentCb cb, void*
 // does not care if paths are relative/portable/absolute.
 LibError path_package_set_dir(PathPackage* pp, const char* dir)
 {
-	// -1 allows for trailing DIR_SEP that will be added if not
+	// -1 allows for trailing '/' that will be added if not
 	// already present.
 	if(strcpy_s(pp->path, ARRAY_SIZE(pp->path)-1, dir) != 0)
 		WARN_RETURN(ERR::PATH_LENGTH);
diff --git a/source/lib/path_util.h b/source/lib/path_util.h
index a869efd735..f07f7c9508 100644
--- a/source/lib/path_util.h
+++ b/source/lib/path_util.h
@@ -28,7 +28,7 @@
 //   must hold at least that much.
 // - unless otherwise mentioned, all functions are intended to work with
 //   native and portable and VFS paths.
-//   when reading, both '/' and DIR_SEP are accepted; '/' is written.
+//   when reading, both '/' and SYS_DIR_SEP are accepted; '/' is written.
 
 #ifndef PATH_UTIL_H__
 #define PATH_UTIL_H__
diff --git a/source/lib/res/file/path.cpp b/source/lib/res/file/path.cpp
index b8ea326605..21ef4f9bca 100644
--- a/source/lib/res/file/path.cpp
+++ b/source/lib/res/file/path.cpp
@@ -58,14 +58,14 @@ enum Conversion
 
 static LibError convert_path(char* dst, const char* src, Conversion conv = TO_NATIVE)
 {
-	// DIR_SEP is assumed to be a single character!
+	// SYS_DIR_SEP is assumed to be a single character!
 
 	const char* s = src;
 	char* d = dst;
 
-	char from = DIR_SEP, to = '/';
+	char from = SYS_DIR_SEP, to = '/';
 	if(conv == TO_NATIVE)
-		from = '/', to = DIR_SEP;
+		from = '/', to = SYS_DIR_SEP;
 
 	size_t len = 0;
 
@@ -190,10 +190,10 @@ LibError file_set_root_dir(const char* argv0, const char* rel_path)
 	if(!realpath(n_path, n_root_dir))
 		return LibError_from_errno();
 
-	// .. append DIR_SEP to simplify code that uses n_root_dir
-	n_root_dir_len = strlen(n_root_dir)+1;	// +1 for trailing DIR_SEP
+	// .. append SYS_DIR_SEP to simplify code that uses n_root_dir
+	n_root_dir_len = strlen(n_root_dir)+1;	// +1 for trailing SYS_DIR_SEP
 	debug_assert((n_root_dir_len+1) < sizeof(n_root_dir)); // Just checking
-	n_root_dir[n_root_dir_len-1] = DIR_SEP;
+	n_root_dir[n_root_dir_len-1] = SYS_DIR_SEP;
 	// You might think that n_root_dir is already 0-terminated, since it's
 	// static - but that might not be true after calling file_reset_root_dir!
 	n_root_dir[n_root_dir_len] = 0;
diff --git a/source/lib/sysdep/sysdep.h b/source/lib/sysdep/sysdep.h
index c22e7b753a..d8c8abc1bd 100644
--- a/source/lib/sysdep/sysdep.h
+++ b/source/lib/sysdep/sysdep.h
@@ -335,9 +335,9 @@ extern i64 i64_from_double(double);
 extern size_t sys_max_sector_size();
 
 #if OS_WIN
-#define DIR_SEP '\\'
+# define SYS_DIR_SEP '\\'
 #else
-#define DIR_SEP '/'
+# define SYS_DIR_SEP '/'
 #endif
 
 // tell the compiler that the code at/following this macro invocation is