diff --git a/Makefile.am b/Makefile.am
index 2852ec1e0..0572be240 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -249,6 +249,7 @@ libutil_a_SOURCES = \
 	src/util/Domain.hxx \
 	src/util/ReusableArray.hxx \
 	src/util/ASCII.hxx \
+	src/util/CharUtil.hxx \
 	src/util/NumberParser.hxx \
 	src/util/StringUtil.cxx src/util/StringUtil.hxx \
 	src/util/FormatString.cxx src/util/FormatString.hxx \