diff --git a/libsqlite3-sys/upgrade.sh b/libsqlite3-sys/upgrade.sh
index ec41f32..34e6b5c 100755
--- a/libsqlite3-sys/upgrade.sh
+++ b/libsqlite3-sys/upgrade.sh
@@ -1,7 +1,6 @@
-#!/bin/bash -e
+#!/bin/sh -e
 
-SCRIPT_DIR=$(cd "$(dirname "$_")" && pwd)
-CUR_DIR=$(pwd -P)
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
 echo "$SCRIPT_DIR"
 cd "$SCRIPT_DIR" || { echo "fatal error" >&2; exit 1; }
 cargo clean
diff --git a/libsqlite3-sys/upgrade_sqlcipher.sh b/libsqlite3-sys/upgrade_sqlcipher.sh
index d087984..ecb5479 100755
--- a/libsqlite3-sys/upgrade_sqlcipher.sh
+++ b/libsqlite3-sys/upgrade_sqlcipher.sh
@@ -1,7 +1,6 @@
-#!/bin/bash -e
+#!/bin/sh -e
 
-SCRIPT_DIR=$(cd "$(dirname "$_")" && pwd)
-CUR_DIR=$(pwd -P)
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
 echo "$SCRIPT_DIR"
 cd "$SCRIPT_DIR" || { echo "fatal error" >&2; exit 1; }
 cargo clean