diff --git a/boost/format/Makefile.am b/boost/format/Makefile.am
index d62d09aa1..773d5118a 100644
--- a/boost/format/Makefile.am
+++ b/boost/format/Makefile.am
@@ -3,4 +3,4 @@ noinst_LIBRARIES = libformat.a
 libformat_a_SOURCES = format_implementation.cc free_funcs.cc parsing.cc
 
 EXTRA_DIST = exceptions.hpp feed_args.hpp format_class.hpp format_fwd.hpp \
- internals.hpp internals_fwd.hpp macros_default.hpp
+ groups.hpp internals.hpp internals_fwd.hpp macros_default.hpp