--- a/build.sh
+++ b/build.sh
@@ -60,7 +60,7 @@
   fi
   CC="sem -j $parallel --id $$ ${CC}"
 fi
-COMP_FLAGS="${CPPFLAGS:-} ${CFLAGS:-} -w -fmax-errors=3 -O3 -fno-strict-aliasing -fno-ident $extraBuildArgs"
+COMP_FLAGS="${CPPFLAGS:-} ${CFLAGS:-} -w -fmax-errors=3 -fno-strict-aliasing -fno-ident $extraBuildArgs"
 LINK_FLAGS="${LDFLAGS:-} "
 PS4=""
 # platform detection