diff --git a/var/spack/repos/builtin/packages/mysql/package.py b/var/spack/repos/builtin/packages/mysql/package.py
index 49b79ec40cf..36964dfa5a4 100644
--- a/var/spack/repos/builtin/packages/mysql/package.py
+++ b/var/spack/repos/builtin/packages/mysql/package.py
@@ -203,7 +203,7 @@ def _fix_dtrace_shebang(self, env):
         copy(dtrace, dtrace_copy)
         filter_file(
             "^#!/usr/bin/python",
-            "#!/usr/bin/env {0}".format(os.path.basename(self.spec["python"].command)),
+            "#!/usr/bin/env {0}".format(os.path.basename(str(self.spec["python"].command))),
             dtrace_copy,
         )
         # To have our own copy of dtrace in PATH, we need to