diff --git a/src/support/filetools.C b/src/support/filetools.C
index 149448c9c8..3eaa5e5879 100644
--- a/src/support/filetools.C
+++ b/src/support/filetools.C
@@ -87,6 +87,8 @@ string const latex_path(string const & original_path,
 		latex_path_dots dots)
 {
 	string path = subst(original_path, "\\", "/");
+	// On cygwin, we may need windows or posix style paths.
+	path = os::latex_path(path);
 	path = subst(path, "~", "\\string~");
 	if (path.find(' ') != string::npos) {
 		// We can't use '"' because " is sometimes active (e.g. if
diff --git a/src/support/os.h b/src/support/os.h
index f9517dcc39..85e97bfa85 100644
--- a/src/support/os.h
+++ b/src/support/os.h
@@ -47,6 +47,14 @@ std::string external_path(std::string const & p);
 /// Converts a host OS style path to unix style.
 std::string internal_path(std::string const & p);
 
+/**
+ * Converts a unix style path into a form suitable for inclusion in a LaTeX
+ * document.
+ * Caution: This function handles only the OS specific part of that task.
+ * Never use it directly, use lyx::support::latex_path instead.
+ */
+std::string latex_path(std::string const & p);
+
 /// Is the path absolute?
 bool is_absolute_path(std::string const & p);
 
diff --git a/src/support/os_cygwin.C b/src/support/os_cygwin.C
index 0961606f1d..dce059d40b 100644
--- a/src/support/os_cygwin.C
+++ b/src/support/os_cygwin.C
@@ -102,6 +102,15 @@ string internal_path(string const & p)
 }
 
 
+string latex_path(string const & p)
+{
+	// We may need a posix style path or a windows style path (depending
+	// on cygwin_path_fix_), but we use always forward slashes, since it
+	// gets written into a .tex file.
+	return external_path(p);
+}
+
+
 bool is_absolute_path(string const & p)
 {
 	if (p.empty())
diff --git a/src/support/os_unix.C b/src/support/os_unix.C
index 2823577313..d53b9345a5 100644
--- a/src/support/os_unix.C
+++ b/src/support/os_unix.C
@@ -63,6 +63,12 @@ string internal_path(string const & p)
 }
 
 
+string latex_path(string const & p)
+{
+	return p;
+}
+
+
 bool is_absolute_path(string const & p)
 {
 	return !p.empty() && p[0] == '/';
diff --git a/src/support/os_win32.C b/src/support/os_win32.C
index 462f6fe3c4..db823e5220 100644
--- a/src/support/os_win32.C
+++ b/src/support/os_win32.C
@@ -216,6 +216,12 @@ string internal_path(string const & p)
 }
 
 
+string latex_path(string const & p)
+{
+	return p;
+}
+
+
 // (Claus H.) On Win32 both Unix and Win32/DOS pathnames are used.
 // Therefore an absolute path could be either a pathname starting
 // with a slash (Unix) or a pathname starting with a drive letter
diff --git a/status.14x b/status.14x
index 1245ba4975..c0c3fb4b31 100644
--- a/status.14x
+++ b/status.14x
@@ -40,6 +40,8 @@ What's new
 - Convert old LyX documents with a float list at the end correctly in
   lyx2lyx (bug 2245).
 
+- Set search path for included files correctly on Cygwin (bug 2409)
+
 * User Interface:
 
 - Convert line endings for external copy/paste on OS X (bug 1955).