diff --git a/boost/Makefile.am b/boost/Makefile.am
index 4fbbf3d02b..b729a6f2b8 100644
--- a/boost/Makefile.am
+++ b/boost/Makefile.am
@@ -12,36 +12,42 @@ AM_CPPFLAGS +=  $(BOOST_INCLUDES)
 
 # This version is more than three times faster than the one below
 
-liblyxboost_la_SOURCES = lyxboost.cpp
+if MONOLITHIC_BOOST
 
-#liblyxboost_la_SOURCES = \
-#	\
-#	libs/iostreams/src/file_descriptor.cpp \
-#	libs/iostreams/src/mapped_file.cpp \
-#	libs/iostreams/src/zlib.cpp \
-#	\
-#	libs/filesystem/src/exception.cpp \
-#	libs/filesystem/src/operations.cpp \
-#	libs/filesystem/src/path.cpp \
-#	libs/filesystem/src/portability.cpp \
-#	\
-#	libs/regex/src/cpp_regex_traits.cpp \
-#	libs/regex/src/c_regex_traits.cpp \
-#	libs/regex/src/cregex.cpp \
-#	libs/regex/src/fileiter.cpp \
-#	libs/regex/src/instances.cpp \
-#	libs/regex/src/regex.cpp \
-#	libs/regex/src/regex_raw_buffer.cpp \
-#	libs/regex/src/regex_traits_defaults.cpp \
-#	libs/regex/src/w32_regex_traits.cpp \
-#	libs/regex/src/posix_api.cpp \
-#	libs/regex/src/wide_posix_api.cpp \
-#	libs/regex/src/regex_debug.cpp \
-#	libs/regex/src/winstances.cpp \
-#	\
-#	libs/signals/src/connection.cpp \
-#	libs/signals/src/named_slot_map.cpp \
-#	libs/signals/src/signal_base.cpp \
-#	libs/signals/src/slot.cpp \
-#	libs/signals/src/trackable.cpp
+liblyxboost_la_SOURCES = \
+	lyxboost.cpp \
+	libs/regex/src/instances.cpp \
+	libs/regex/src/cpp_regex_traits.cpp \
+	libs/regex/src/c_regex_traits.cpp 
 
+else
+
+liblyxboost_la_SOURCES = \
+	\
+	libs/iostreams/src/file_descriptor.cpp \
+	libs/iostreams/src/mapped_file.cpp \
+	libs/iostreams/src/zlib.cpp \
+	\
+	libs/filesystem/src/exception.cpp \
+	libs/filesystem/src/operations.cpp \
+	libs/filesystem/src/path.cpp \
+	libs/filesystem/src/portability.cpp \
+	\
+	libs/regex/src/cregex.cpp \
+	libs/regex/src/fileiter.cpp \
+	libs/regex/src/regex.cpp \
+	libs/regex/src/regex_raw_buffer.cpp \
+	libs/regex/src/regex_traits_defaults.cpp \
+	libs/regex/src/w32_regex_traits.cpp \
+	libs/regex/src/posix_api.cpp \
+	libs/regex/src/wide_posix_api.cpp \
+	libs/regex/src/regex_debug.cpp \
+	libs/regex/src/winstances.cpp \
+	\
+	libs/signals/src/connection.cpp \
+	libs/signals/src/named_slot_map.cpp \
+	libs/signals/src/signal_base.cpp \
+	libs/signals/src/slot.cpp \
+	libs/signals/src/trackable.cpp
+
+endif
diff --git a/boost/lyxboost.cpp b/boost/lyxboost.cpp
index f524328fd9..a41e1bd5ad 100644
--- a/boost/lyxboost.cpp
+++ b/boost/lyxboost.cpp
@@ -7,11 +7,11 @@
 #include "libs/filesystem/src/path.cpp"
 #include "libs/filesystem/src/portability.cpp"
 
-#include "libs/regex/src/cpp_regex_traits.cpp"
-#include "libs/regex/src/c_regex_traits.cpp"
+//#include "libs/regex/src/cpp_regex_traits.cpp"
+//#include "libs/regex/src/c_regex_traits.cpp"
 #include "libs/regex/src/cregex.cpp"
 #include "libs/regex/src/fileiter.cpp"
-#include "libs/regex/src/instances.cpp"
+//#include "libs/regex/src/instances.cpp"
 #include "libs/regex/src/regex.cpp"
 #include "libs/regex/src/regex_raw_buffer.cpp"
 #include "libs/regex/src/regex_traits_defaults.cpp"