diff --git a/src/halmos/config.py b/src/halmos/config.py
index dcf567ca..e7f10381 100644
--- a/src/halmos/config.py
+++ b/src/halmos/config.py
@@ -441,7 +441,7 @@ class Config:
 
     solver_command: str = arg(
         help="use the given command when invoking the solver",
-        global_default="z3",
+        global_default="z3.exe" if os.name == "nt" else "z3",
         metavar="COMMAND",
         group=solver,
     )