diff --git a/flopy/mbase.py b/flopy/mbase.py
index ac989f2a6..99e32bf1f 100644
--- a/flopy/mbase.py
+++ b/flopy/mbase.py
@@ -98,7 +98,7 @@ def _resolve(exe_name):
             f"The program {exe_name} does not exist or is not executable."
         )
 
-    return exe_path
+    return str(exe_path)
 
 
 # external exceptions for users