diff --git a/lib/BasicsC/local-configuration.h.in b/lib/BasicsC/local-configuration.h.in
index 59177b6ce7..a9732f989f 100644
--- a/lib/BasicsC/local-configuration.h.in
+++ b/lib/BasicsC/local-configuration.h.in
@@ -77,12 +77,6 @@
 
 #undef TRI_ENABLE_MAINTAINER_MODE
 
-////////////////////////////////////////////////////////////////////////////////
-/// @brief use MRUBY as alternative/addition to JavaScript
-////////////////////////////////////////////////////////////////////////////////
-
-#undef TRI_ENABLE_MRUBY
-
 ////////////////////////////////////////////////////////////////////////////////
 /// @brief configure command
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/m4/all-in-one.mruby b/m4/all-in-one.mruby
index 52230272f2..56972715aa 100644
--- a/m4/all-in-one.mruby
+++ b/m4/all-in-one.mruby
@@ -15,7 +15,7 @@ AC_ARG_ENABLE(mruby,
 )
 
 if test "x$tr_MRUBY" = "xyes";  then
-  MRUBY_CPPFLAGS="-I${srcdir}/3rdParty/mruby/include"
+  MRUBY_CPPFLAGS="-I${srcdir}/3rdParty/mruby/include -DTRI_ENABLE_MRUBY=1"
   MRUBY_LDFLAGS=""
   MRUBY_LIBS="${srcdir}/3rdParty/mruby/build/host/lib/libmruby.a"