diff --git a/pysr/export_sympy.py b/pysr/export_sympy.py
index 81142f48..c3e2f7f0 100644
--- a/pysr/export_sympy.py
+++ b/pysr/export_sympy.py
@@ -47,6 +47,8 @@
     "ceil": sympy.ceiling,
     "sign": sympy.sign,
     "gamma": sympy.gamma,
+    "logical_or": lambda x, y: sympy.Piecewise((1.0, 0.0), ((x > 0) | (y > 0), True)),
+    "logical_and": lambda x, y: sympy.Piecewise((1.0, 0.0), ((x > 0) & (y > 0), True)),
 }