--- a/Makefile.am
+++ b/Makefile.am
@@ -30,7 +30,8 @@
   include/getopt++/DefaultFormatter.h \
   include/getopt++/GetOption.h \
   include/getopt++/OptionSet.h \
-  include/getopt++/StringOption.h
+  include/getopt++/StringOption.h \
+  include/getopt++/StringCollector.h
 
 tests_testoption_SOURCES = tests/testoption.cc
 tests_testoption_LDADD = libgetopt++.la
--- a/Makefile.in
+++ b/Makefile.in
@@ -241,7 +241,8 @@
   include/getopt++/DefaultFormatter.h \
   include/getopt++/GetOption.h \
   include/getopt++/OptionSet.h \
-  include/getopt++/StringOption.h
+  include/getopt++/StringOption.h \
+  include/getopt++/StringCollector.h
 
 tests_testoption_SOURCES = tests/testoption.cc
 tests_testoption_LDADD = libgetopt++.la