diff --git a/var/spack/repos/builtin/packages/libtool/package.py b/var/spack/repos/builtin/packages/libtool/package.py
index decc4b114e..60a922c881 100644
--- a/var/spack/repos/builtin/packages/libtool/package.py
+++ b/var/spack/repos/builtin/packages/libtool/package.py
@@ -3,7 +3,8 @@
 #
 # SPDX-License-Identifier: (Apache-2.0 OR MIT)
 
-from spack import *
+import os
+import re
 
 
 class Libtool(AutotoolsPackage, GNUMirrorPackage):
@@ -30,6 +31,14 @@ class Libtool(AutotoolsPackage, GNUMirrorPackage):
 
     build_directory = 'spack-build'
 
+    executables = ['^g?libtool(ize)?$']
+
+    @classmethod
+    def determine_version(cls, exe):
+        output = Executable(exe)('--version', output=str, error=os.devnull)
+        match = re.search(r'\(GNU libtool\)\s+(\S+)', output)
+        return match.group(1) if match else None
+
     @when('@2.4.2,develop')
     def autoreconf(self, spec, prefix):
         Executable('./bootstrap')()