diff --git a/preprocessor.cpp b/preprocessor.cpp
index e74b1366b..93becaf13 100644
--- a/preprocessor.cpp
+++ b/preprocessor.cpp
@@ -19,11 +19,26 @@
 
 #include "preprocessor.h"
 
+#include <algorithm>
 #include <list>
 #include <sstream>
 
+/**
+ * Get all possible configurations. By looking at the ifdefs and ifndefs in filedata
+ */
+static std::list<std::string> getcfgs( const std::string &filedata );
+
+/**
+ * Get preprocessed code for a given configuration
+ */
 static std::string getcode(const std::string &filedata, std::string cfg);
 
+
+/**
+ * Extract the code for each configuration
+ * \param istr The (file/string) stream to read from.
+ * \param result The map that will get the results
+ */
 void preprocess(std::istream &istr, std::map<std::string, std::string> &result)
 {
     std::ostringstream ostr;
@@ -31,12 +46,42 @@ void preprocess(std::istream &istr, std::map<std::string, std::string> &result)
     while ( getline(istr, line) )
         ostr << line << "\n";
 
+    // Get all possible configurations..
+    std::list<std::string> cfgs = getcfgs( ostr.str() );
+
+    // Extract the code for each possible configuration..
     result.clear();
-    result[""] = getcode( ostr.str(), "" );
-    result["WIN32"] = getcode( ostr.str(), "WIN32" );
+    for ( std::list<std::string>::const_iterator it = cfgs.begin(); it != cfgs.end(); ++it )
+    {
+        result[ *it ] = getcode( ostr.str(), *it );
+    }
 }
 
 
+
+static std::list<std::string> getcfgs( const std::string &filedata )
+{
+    std::list<std::string> ret;
+    ret.push_back("");
+
+    std::istringstream istr(filedata);
+    std::string line;
+    while ( getline(istr, line) )
+    {
+        if ( line.find("#ifdef ")==0 || line.find("#ifndef ")==0 )
+        {
+            std::string def( line.substr(line.find(" ") + 1) );
+            if (std::find(ret.begin(), ret.end(), def) == ret.end())
+                ret.push_back( def );
+        }
+    }
+
+    return ret;
+}
+
+
+
+
 static std::string getcode(const std::string &filedata, std::string cfg)
 {
     std::ostringstream ret;
@@ -50,6 +95,9 @@ static std::string getcode(const std::string &filedata, std::string cfg)
         if ( line.find("#ifdef ") == 0 )
             matching_ifdef.push_back( !cfg.empty() && line.find(cfg) != std::string::npos );
 
+        else if ( line.find("#ifndef ") == 0 )
+            matching_ifdef.push_back( cfg.empty() || line.find(cfg) == std::string::npos );
+
         else if ( line.find("#else") == 0)
             matching_ifdef.back() = ! matching_ifdef.back();
 
diff --git a/testpreprocessor.cpp b/testpreprocessor.cpp
index 7b828519a..61f33f012 100644
--- a/testpreprocessor.cpp
+++ b/testpreprocessor.cpp
@@ -38,6 +38,7 @@ private:
     void run()
     {
         TEST_CASE( test1 );
+        TEST_CASE( test2 );
     }
 
     void check(const char filedata[], const std::map<std::string,std::string> &expected)
@@ -71,6 +72,21 @@ private:
 
         check( filedata, expected );
     }
+
+    void test2()
+    {
+        const char filedata[] = "#ifndef WIN32\n"
+                                "    abcdef\n"
+                                "#else\n"
+                                "    qwerty\n"
+                                "#endif\n";
+
+        std::map<std::string, std::string> expected;
+        expected[""]      = "\n    abcdef\n\n\n\n";
+        expected["WIN32"] = "\n\n\n    qwerty\n\n";
+
+        check( filedata, expected );
+    }
 };
 
 REGISTER_TEST( TestPreprocessor )