diff --git a/build-aux/build-ports.sh b/build-aux/build-ports.sh
index da9ba4c1..5e0314d5 100755
--- a/build-aux/build-ports.sh
+++ b/build-aux/build-ports.sh
@@ -41,7 +41,7 @@ SORTIX_PORTS_DIR=$(make_dir_path_absolute "$SORTIX_PORTS_DIR")
 SORTIX_REPOSITORY_DIR=$(make_dir_path_absolute "$SORTIX_REPOSITORY_DIR")
 
 # Decide the optimization options with which the ports will be built.
-if [ -z "${OPTLEVEL+x}" ]; then OPTLEVEL="-Os"; fi
+if [ -z "${OPTLEVEL+x}" ]; then OPTLEVEL="-Os -s"; fi
 if [ -z "${PORTS_OPTLEVEL+x}" ]; then PORTS_OPTLEVEL="$OPTLEVEL"; fi
 if [ -z "${PORTS_CFLAGS+x}" ]; then PORTS_CFLAGS="$PORTS_OPTLEVEL"; fi
 if [ -z "${PORTS_CXXFLAGS+x}" ]; then PORTS_CXXFLAGS="$PORTS_OPTLEVEL"; fi
diff --git a/build-aux/compiler.mak b/build-aux/compiler.mak
index 6447d0fb..73dd5c67 100644
--- a/build-aux/compiler.mak
+++ b/build-aux/compiler.mak
@@ -121,7 +121,7 @@ ifdef SYSROOT
 endif
 
 # Determine default optimization level.
-DEFAULT_GENERIC_OPTLEVEL_BASE:=-O2 -g
+DEFAULT_GENERIC_OPTLEVEL_BASE:=-Os -s
 DEFAULT_OPTLEVEL_FOR_BUILD:=$(DEFAULT_GENERIC_OPTLEVEL_BASE)
 ifeq ($(BUILD_IS_SORTIX),1)
   DEFAULT_OPTLEVEL_FOR_BUILD+=