diff --git a/Makefile.gcc8 b/Makefile.gcc
similarity index 94%
rename from Makefile.gcc8
rename to Makefile.gcc
index bca961c..38cfb78 100644
--- a/Makefile.gcc8
+++ b/Makefile.gcc
@@ -7,8 +7,8 @@
 # See BSD-3-Clause license in README.md
 #
 
-CFLAGS=-I inc -I test -O3 -Wcast-align -Wall -Werror -pedantic-errors -Wextra -Wshadow -Wparentheses -xc -std=c99 -Werror=maybe-uninitialized
-CC=/usr/local/bin/gcc-8
+CFLAGS=-I inc -I test -Os -Wcast-align -Wall -Werror -pedantic-errors -Wextra -Wshadow -Wparentheses -xc -std=c99 -Werror=maybe-uninitialized
+CC=/usr/local/bin/gcc-9
 
 QCBOR_OBJ=src/UsefulBuf.o src/qcbor_encode.o src/qcbor_decode.o src/ieee754.o