--- a/configure.ac
+++ b/configure.ac
@@ -15,8 +15,6 @@
 AC_DEFINE_UNQUOTED([BUILD_DATE], ["`/bin/date`"],
 		   [date wavemon was last configured and built])
 
-CFLAGS="-O2 -Wall"
-
 # wavemon is only supported on Linux, warn user about futile compilations
 AC_CANONICAL_HOST
 case "$host_os" in
diff -uarN a/Makefile.in b/Makefile.in
--- a/Makefile.in	2017-07-14 21:35:18.154423280 +0300
+++ b/Makefile.in	2017-07-14 21:35:34.613402738 +0300
@@ -9,7 +9,7 @@
 install-suid-root: exec_perms = 4755
 
 CC	 ?= @CC@
-CFLAGS	 ?= @CFLAGS@ @LIBNL3_CFLAGS@
+CFLAGS	 = @CFLAGS@ @LIBNL3_CFLAGS@
 CPPFLAGS ?= @CPPFLAGS@
 LDFLAGS  ?= @LDFLAGS@
 DEFS	 ?= @DEFS@
@@ -25,8 +25,7 @@
 DOCS	= README.md NEWS THANKS AUTHORS COPYING ChangeLog
 
 %.o: %.c $(HEADERS)
-	@echo ' CC  ' $<
-	@$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(DEFS) -c -o $@ $<
+	$(CC) $(CFLAGS) $(CPPFLAGS) $(LDFLAGS) $(DEFS) -c -o $@ $<
 
 all: @PACKAGE_NAME@
 @PACKAGE_NAME@: $(MAIN) $(OBJS)