diff --git a/src/Makefile.am b/src/Makefile.am
index dc478a5aa3..355236739a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -76,6 +76,7 @@ noinst_HEADERS = \
 	request_body_processor/*.h \
 	utils/*.h \
 	variables/*.h \
+	engine/*.h \
 	*.h