diff --git a/src/api/python/z3/z3.py b/src/api/python/z3/z3.py
index 60a9bd734..7711ec4cd 100644
--- a/src/api/python/z3/z3.py
+++ b/src/api/python/z3/z3.py
@@ -7241,11 +7241,13 @@ class Optimize(Z3PPObject):
     def assert_exprs(self, *args):
         """Assert constraints as background axioms for the optimize solver."""
         args = _get_args(args)
+        s    = BoolSort(self.ctx)
         for arg in args:
             if isinstance(arg, Goal) or isinstance(arg, AstVector):
                 for f in arg:
                     Z3_optimize_assert(self.ctx.ref(), self.optimize, f.as_ast())
             else:
+                arg = s.cast(arg)
                 Z3_optimize_assert(self.ctx.ref(), self.optimize, arg.as_ast())
 
     def add(self, *args):