Index: src/Makefile.am
===================================================================
--- src/Makefile.am	(revision b72d4ed3c032c44b2e77aa0b0822f63ebaf1bea0)
+++ src/Makefile.am	(revision ff919a3804e36495cd46c3454fcb6dc243afd5ab)
@@ -43,5 +43,5 @@
 driver_cfa_cpp_SOURCES = ${SRC}
 driver_cfa_cpp_LDADD = ${LEXLIB} -ldl			# yywrap
-driver_cfa_cpp_CXXFLAGS = -Wno-deprecated -Wall -DDEBUG_ALL -I${abs_top_srcdir}/src/include -DYY_NO_INPUT -O2 -g -std=c++14
+driver_cfa_cpp_CXXFLAGS = -Wno-deprecated -Wall -Wextra -DDEBUG_ALL -I${abs_top_srcdir}/src/include -DYY_NO_INPUT -O2 -g -std=c++14
 driver_cfa_cpp_LDFLAGS = -Xlinker -export-dynamic
 
Index: src/Makefile.in
===================================================================
--- src/Makefile.in	(revision b72d4ed3c032c44b2e77aa0b0822f63ebaf1bea0)
+++ src/Makefile.in	(revision ff919a3804e36495cd46c3454fcb6dc243afd5ab)
@@ -544,5 +544,5 @@
 driver_cfa_cpp_SOURCES = ${SRC}
 driver_cfa_cpp_LDADD = ${LEXLIB} -ldl			# yywrap
-driver_cfa_cpp_CXXFLAGS = -Wno-deprecated -Wall -DDEBUG_ALL -I${abs_top_srcdir}/src/include -DYY_NO_INPUT -O2 -g -std=c++14
+driver_cfa_cpp_CXXFLAGS = -Wno-deprecated -Wall -Wextra -DDEBUG_ALL -I${abs_top_srcdir}/src/include -DYY_NO_INPUT -O2 -g -std=c++14
 driver_cfa_cpp_LDFLAGS = -Xlinker -export-dynamic
 all: $(BUILT_SOURCES)