diff --git a/alib2str/src/grammar/string/ContextFree/CFG.cpp b/alib2str/src/grammar/string/ContextFree/CFG.cxx
similarity index 52%
rename from alib2str/src/grammar/string/ContextFree/CFG.cpp
rename to alib2str/src/grammar/string/ContextFree/CFG.cxx
index 4bf3f26b8a3584c697df105949680e788f1dc9bc..8c0b5aa817f57228530d51e59709c6b05fca8fd8 100644
--- a/alib2str/src/grammar/string/ContextFree/CFG.cpp
+++ b/alib2str/src/grammar/string/ContextFree/CFG.cxx
@@ -12,7 +12,7 @@
 
 namespace {
 
-auto stringWrite = registration::StringWriterRegister < grammar::CFG < > > ( );
-auto stringReader = registration::StringReaderRegister < grammar::Grammar, grammar::CFG < > > ( );
+auto stringWriteCFG = registration::StringWriterRegister < grammar::CFG < > > ( );
+auto stringReaderCFG = registration::StringReaderRegister < grammar::Grammar, grammar::CFG < > > ( );
 
 } /* namespace */
diff --git a/alib2str/src/grammar/string/ContextFree/CNF.cpp b/alib2str/src/grammar/string/ContextFree/CNF.cxx
similarity index 52%
rename from alib2str/src/grammar/string/ContextFree/CNF.cpp
rename to alib2str/src/grammar/string/ContextFree/CNF.cxx
index 54594f0134826788316bd91a1d9effd8525c018f..358624a0a21a07583c6c948913ec27beff1d9cd8 100644
--- a/alib2str/src/grammar/string/ContextFree/CNF.cpp
+++ b/alib2str/src/grammar/string/ContextFree/CNF.cxx
@@ -12,7 +12,7 @@
 
 namespace {
 
-auto stringWrite = registration::StringWriterRegister < grammar::CNF < > > ( );
-auto stringReader = registration::StringReaderRegister < grammar::Grammar, grammar::CNF < > > ( );
+auto stringWriteCNF = registration::StringWriterRegister < grammar::CNF < > > ( );
+auto stringReaderCNF = registration::StringReaderRegister < grammar::Grammar, grammar::CNF < > > ( );
 
 } /* namespace */
diff --git a/alib2str/src/grammar/string/ContextFree/ContextFree.cpp b/alib2str/src/grammar/string/ContextFree/ContextFree.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..adb4f75bf49e98d760383ace0e604d707619de6e
--- /dev/null
+++ b/alib2str/src/grammar/string/ContextFree/ContextFree.cpp
@@ -0,0 +1,5 @@
+#include "CFG.cxx"
+#include "CNF.cxx"
+#include "EpsilonFreeCFG.cxx"
+#include "GNF.cxx"
+#include "LG.cxx"
diff --git a/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cpp b/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cpp
deleted file mode 100644
index 16fc2cb9e11b9ff680400ebaeb863c6f1c5815cf..0000000000000000000000000000000000000000
--- a/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cpp
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * EpsilonFreeCFG.cpp
- *
- * Created on: Sep 27, 2017
- * Author: Jan Travnicek
- */
-
-#include "EpsilonFreeCFG.h"
-#include <grammar/Grammar.h>
-
-#include <registration/StringRegistration.hpp>
-
-namespace {
-
-auto stringWrite = registration::StringWriterRegister < grammar::EpsilonFreeCFG < > > ( );
-auto stringReader = registration::StringReaderRegister < grammar::Grammar, grammar::EpsilonFreeCFG < > > ( );
-
-} /* namespace */
diff --git a/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cxx b/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cxx
new file mode 100644
index 0000000000000000000000000000000000000000..d927c19478bfe0df79c131ac5bc598db4b94a5d8
--- /dev/null
+++ b/alib2str/src/grammar/string/ContextFree/EpsilonFreeCFG.cxx
@@ -0,0 +1,18 @@
+/*
+ * EpsilonFreeCFG.cpp
+ *
+ * Created on: Sep 27, 2017
+ * Author: Jan Travnicek
+ */
+
+#include "EpsilonFreeCFG.h"
+#include <grammar/Grammar.h>
+
+#include <registration/StringRegistration.hpp>
+
+namespace {
+
+auto stringWriteEpsilonFreeCFG = registration::StringWriterRegister < grammar::EpsilonFreeCFG < > > ( );
+auto stringReaderEpsilonFreeCFG = registration::StringReaderRegister < grammar::Grammar, grammar::EpsilonFreeCFG < > > ( );
+
+} /* namespace */
diff --git a/alib2str/src/grammar/string/ContextFree/GNF.cpp b/alib2str/src/grammar/string/ContextFree/GNF.cxx
similarity index 52%
rename from alib2str/src/grammar/string/ContextFree/GNF.cpp
rename to alib2str/src/grammar/string/ContextFree/GNF.cxx
index 31dedaf57d35268523262df30a586b94f619856a..513835293ca232b02b02dd7eae4b09bcd238aa56 100644
--- a/alib2str/src/grammar/string/ContextFree/GNF.cpp
+++ b/alib2str/src/grammar/string/ContextFree/GNF.cxx
@@ -12,7 +12,7 @@
 
 namespace {
 
-auto stringWrite = registration::StringWriterRegister < grammar::GNF < > > ( );
-auto stringReader = registration::StringReaderRegister < grammar::Grammar, grammar::GNF < > > ( );
+auto stringWriteGNF = registration::StringWriterRegister < grammar::GNF < > > ( );
+auto stringReaderGNF = registration::StringReaderRegister < grammar::Grammar, grammar::GNF < > > ( );
 
 } /* namespace */
diff --git a/alib2str/src/grammar/string/ContextFree/LG.cpp b/alib2str/src/grammar/string/ContextFree/LG.cxx
similarity index 52%
rename from alib2str/src/grammar/string/ContextFree/LG.cpp
rename to alib2str/src/grammar/string/ContextFree/LG.cxx
index daf5f290d2e24054287546b3f6054df8f937af0a..dbd8ad749b8b634df7a5c98bcb33af4340cd949d 100644
--- a/alib2str/src/grammar/string/ContextFree/LG.cpp
+++ b/alib2str/src/grammar/string/ContextFree/LG.cxx
@@ -12,7 +12,7 @@
 
 namespace {
 
-auto stringWrite = registration::StringWriterRegister < grammar::LG < > > ( );
-auto stringReader = registration::StringReaderRegister < grammar::Grammar, grammar::LG < > > ( );
+auto stringWriteLG = registration::StringWriterRegister < grammar::LG < > > ( );
+auto stringReaderLG = registration::StringReaderRegister < grammar::Grammar, grammar::LG < > > ( );
 
 } /* namespace */