diff --git a/ast_expr.cpp b/ast_expr.cpp
index ad29cdc68d7..4e83decb924 100644
--- a/ast_expr.cpp
+++ b/ast_expr.cpp
@@ -50,6 +50,7 @@ ast_expression::operator_string(enum ast_operators op)
       "~",
       "&&",
       "^^",
+      "||",
       "!",
 
       "*=",
@@ -64,6 +65,7 @@ ast_expression::operator_string(enum ast_operators op)
       "|=",
 
       "?:",
+
       "++",
       "--",
       "++",
@@ -71,6 +73,8 @@ ast_expression::operator_string(enum ast_operators op)
       ".",
    };
 
+   assert((unsigned int)op < sizeof(operators) / sizeof(operators[0]));
+
    return operators[op];
 }