diff --git a/build-package.sh b/build-package.sh
index 6d9ada3f3..d00515f6a 100755
--- a/build-package.sh
+++ b/build-package.sh
@@ -571,7 +571,12 @@ termux_step_setup_toolchain() {
 	if [ -n "$TERMUX_DEBUG" ]; then
 		CFLAGS+=" -g3 -O1 -fstack-protector --param ssp-buffer-size=4 -D_FORTIFY_SOURCE=2"
 	else
-		CFLAGS+=" -Os"
+		if [ "$TERMUX_PKG_CLANG" = "no" ]; then
+			CFLAGS+=" -Os"
+		else
+			# -Oz seems good for clang, see https://github.com/android-ndk/ndk/issues/133
+			CFLAGS+=" -Oz"
+		fi
 	fi
 
 	export CXXFLAGS="$CFLAGS"