diff --git a/include/tclap/Makefile.am b/include/tclap/Makefile.am
index 7a2c350..0e247bf 100644
--- a/include/tclap/Makefile.am
+++ b/include/tclap/Makefile.am
@@ -22,5 +22,7 @@ libtclapinclude_HEADERS = \
 			 ZshCompletionOutput.h \
 			 OptionalUnlabeledTracker.h \
 			 Constraint.h \
-			 ValuesConstraint.h
+			 ValuesConstraint.h \
+			 ArgTraits.h \
+			 StandardTraits.h