diff --git a/toolchains/macosx-common/packages/libsdl2/build.sh b/toolchains/macosx-common/packages/libsdl2/build.sh
index 2800a0e..72fc29c 100755
--- a/toolchains/macosx-common/packages/libsdl2/build.sh
+++ b/toolchains/macosx-common/packages/libsdl2/build.sh
@@ -1,3 +1,5 @@
+#! /bin/sh
+
 PACKAGE_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
 HELPERS_DIR=$PACKAGE_DIR/../..
 . $HELPERS_DIR/functions.sh