diff --git a/alib2algo/src/regexp/properties/Properties.cpp b/alib2algo/src/regexp/properties/Properties.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b13994763aa22d755b71ed6dd30f5b72a7206f11
--- /dev/null
+++ b/alib2algo/src/regexp/properties/Properties.cpp
@@ -0,0 +1,2 @@
+#include "RegExpEmpty.cxx"
+#include "RegExpEpsilon.cxx"
diff --git a/alib2algo/src/regexp/properties/RegExpEmpty.cpp b/alib2algo/src/regexp/properties/RegExpEmpty.cxx
similarity index 100%
rename from alib2algo/src/regexp/properties/RegExpEmpty.cpp
rename to alib2algo/src/regexp/properties/RegExpEmpty.cxx
diff --git a/alib2algo/src/regexp/properties/RegExpEpsilon.cpp b/alib2algo/src/regexp/properties/RegExpEpsilon.cxx
similarity index 100%
rename from alib2algo/src/regexp/properties/RegExpEpsilon.cpp
rename to alib2algo/src/regexp/properties/RegExpEpsilon.cxx