diff --git a/README.md b/README.md
index 48c3f57..1e418fc 100644
--- a/README.md
+++ b/README.md
@@ -76,9 +76,8 @@ Installation
 
 5. Set bluepy-helper capability
     ```
-    ./setcap.sh
-    Set up bluepy-helper capability to allow use by normal users
-    /usr/lib/python3.8/site-packages/bluepy-1.3.0-py3.8.egg/bluepy/bluepy-helper = cap_net_admin,cap_net_raw+eip
+    $ sudo ./bluepy_helper_cap.py
+    Set capacbility 'cap_net_raw,cap_net_admin' to /usr/lib/python3.8/site-packages/bluepy-1.3.0-py3.8.egg/bluepy/bluepy-helper
     ```
 
 6. If using a micro:bit, install Scratch-link hex on your device.
diff --git a/bluepy_helper_cap.py b/bluepy_helper_cap.py
new file mode 100755
index 0000000..00de779
--- /dev/null
+++ b/bluepy_helper_cap.py
@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+
+import sys
+import os
+import shutil
+import bluepy
+import subprocess
+
+import logging
+logLevel = logging.INFO
+
+# for logging
+logger = logging.getLogger(__name__)
+formatter = logging.Formatter(fmt='%(asctime)s %(message)s')
+handler = logging.StreamHandler()
+handler.setLevel(logLevel)
+handler.setFormatter(formatter)
+logger.setLevel(logLevel)
+logger.addHandler(handler)
+logger.propagate = False
+
+# Check dependent tools
+DEPENDENT_TOOLS = {
+    "setcap": "libcap2-bin (Ubuntu) or libcap (Arch)",
+}
+
+for cmd in DEPENDENT_TOOLS:
+    if not shutil.which(cmd):
+        print(f"'{cmd}' not found. Install package {DEPENDENT_TOOLS[cmd]}.")
+        sys.exit(1)
+
+def helper_path():
+    path = os.path.abspath(bluepy.__file__)
+    if not path:
+        logger.error("Bluepy module not found")
+        sys.exit(1)
+    if path.find("__init__.py") < 0:
+        logger.error(f"Unexpected bluepy module path: {path}")
+        sys.exit(1)
+    path = path.replace("__init__.py", "bluepy-helper")
+    return path
+
+def is_set():
+    path = helper_path()
+    p = subprocess.run(["getcap", path], capture_output=True)
+    if p.returncode !=0:
+        logger.error(f"Failed to get capability of {path}")
+        return False
+    out = str(p.stdout)
+    return out.find("cap_net_admin") >= 0 and out.find("cap_net_raw") >= 0
+
+def setcap():
+    path = helper_path()
+    if is_set():
+        return True
+    p = subprocess.run(["setcap", "cap_net_raw,cap_net_admin+eip", path], \
+                       capture_output=True)
+    if p.returncode !=0:
+        logger.error(f"Failed to set capability to {path}")
+        return False
+    print(f"Set capacbility 'cap_net_raw,cap_net_admin' to {path}")
+    return True
+
+if __name__ == "__main__":
+    setcap()
diff --git a/scratch_link.py b/scratch_link.py
index f577a69..9d9945a 100755
--- a/scratch_link.py
+++ b/scratch_link.py
@@ -21,6 +21,7 @@ import bluetooth
 # for BLESession (e.g. BBC micro:bit)
 from bluepy.btle import Scanner, UUID, Peripheral, DefaultDelegate
 from bluepy.btle import BTLEDisconnectError, BTLEManagementError
+import bluepy_helper_cap
 
 import threading
 import time
@@ -518,6 +519,11 @@ class BLESession(Session):
         err_msg = None
 
         if self.status == self.INITIAL and method == 'discover':
+            if not bluepy_helper_cap.is_set():
+                logger.error("Capability is not set to bluepy helper.")
+                logger.error("Run bluepy_setcap.py with root privilege.")
+                logger.error("e.g. $ sudo bluepy_helper_cap.py")
+                sys.exit(1)
             found_ifaces = 0
             for i in range(self.MAX_SCANNER_IF):
                 scanner = Scanner(iface=i)
diff --git a/setcap.sh b/setcap.sh
deleted file mode 100755
index df58ccf..0000000
--- a/setcap.sh
+++ /dev/null
@@ -1,6 +0,0 @@
-#!/bin/sh
-echo "Set up bluepy-helper capability to allow use by normal users"
-find /usr -name bluepy-helper -exec sudo setcap \
-     'cap_net_raw,cap_net_admin+eip' {} \; 2> /dev/null
-find /usr -name bluepy-helper -exec sudo getcap {} \; 2> /dev/null
-