diff --git a/src/Simplify_Stmts.cpp b/src/Simplify_Stmts.cpp
index b1bac9f361d3..5be05e42e6c6 100644
--- a/src/Simplify_Stmts.cpp
+++ b/src/Simplify_Stmts.cpp
@@ -63,7 +63,11 @@ Stmt Simplify::visit(const IfThenElse *op) {
     if (else_unreachable) {
         return then_case;
     } else if (then_unreachable) {
-        return else_case;
+        if (else_case.defined()) {
+            return else_case;
+        } else {
+            return Evaluate::make(0);
+        }
     }
 
     if (is_no_op(else_case)) {