diff --git a/src/driver.cpp b/src/driver.cpp
index 3165ed5..23d1ef7 100644
--- a/src/driver.cpp
+++ b/src/driver.cpp
@@ -4,15 +4,32 @@
 #include <iostream>
 #include <fstream>
 
+namespace {
+    /**
+     * Filter only valid identifier chars: alphanumeric, and not starting with a digit
+     */
+    std::string clean(std::string in) {
+        std::string s;
+        for (char c : in) {
+            if ((s.length() && std::isalnum(c)) || std::isalpha(c))
+                s += c;
+        }
+        return s;
+    }
+}
+
 namespace lxs {
     Driver::Driver(std::unique_ptr<BackendManager> backends, std::istream& inputfile, std::string outputdir, std::string language, std::string lexername) :
                 m_backends(std::move(backends)),
                 m_inputfile(inputfile),
                 m_outputdir(outputdir),
                 m_language(language),
-                m_lexername(lexername)
+                m_lexername(clean(lexername))
     {
-        //TODO clean lexername
+        if (!m_lexername.length()) {
+            std::cerr << "No valid lexer name possible" << std::endl;
+            exit(1);
+        }
     }
 
     Driver::~Driver()
diff --git a/src/main.cpp b/src/main.cpp
index 0e0c834..e2dd158 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -29,14 +29,35 @@ int main(int argc, char** argv) {
         return 1;
     }
 
+#ifdef _WIN32
+    const char PATHSEP = '\\';
+#else
+    const char PATHSEP = '/';
+#endif
+
     std::string lexername = options["lexername"];
-    //FIXME: this really needs some more work...
-    if (!lexername.length()) {
+
+    if (!lexername.length()) { //The option is empty
         if (args[0].length() >= 4 && args[0].substr(args[0].length() - 4, 4) == ".lxs") {
             lexername = args[0].substr(0, args[0].length() - 4); //Drop the .lxs
+
         } else {
             lexername = args[0];
         }
+
+        std::size_t pos;
+        // '/' can be used on most platforms (even windows)
+        pos = lexername.find_last_of('/');
+        if (pos != lexername.npos) {
+            lexername = lexername.substr(pos + 1);
+        }
+
+        // strip platform specific as well
+        pos = lexername.find_last_of(PATHSEP);
+        if (pos != lexername.npos) {
+            lexername = lexername.substr(pos + 1);
+        }
+
     }
 
     std::unique_ptr<lxs::BackendManager> backends(new lxs::BackendManager());