diff --git a/exprtk.hpp b/exprtk.hpp
index 9a5def6..802955a 100644
--- a/exprtk.hpp
+++ b/exprtk.hpp
@@ -20590,8 +20590,8 @@ namespace exprtk
                     details::is_return_node(right_branch)
                   )
                {
-                  free_node(node_allocator_,  expression);
-                  free_node(node_allocator_,right_branch);
+                  free_node(node_allocator_,   expression);
+                  free_node(node_allocator_, right_branch);
 
                   set_error(
                      make_error(parser_error::e_syntax,
@@ -20623,7 +20623,8 @@ namespace exprtk
                                 exprtk_error_location));
                }
 
-               free_node(node_allocator_,expression);
+               free_node(node_allocator_,   expression);
+               free_node(node_allocator_, right_branch);
 
                return error_node();
             }
diff --git a/exprtk_test.cpp b/exprtk_test.cpp
index dbff457..75747aa 100644
--- a/exprtk_test.cpp
+++ b/exprtk_test.cpp
@@ -2811,7 +2811,16 @@ inline bool run_test03()
                                    "1 v x",
                                    "1 v y",
                                    "x v 1",
-                                   "y v 1"
+                                   "y v 1",
+                                   
+                                   "(x == 'a string'                    )",
+                                   "(x == 'a string'[1:2]               )",
+                                   "(x == 'a string' + 'b string'       )",
+                                   "(x == ('a string' + 'b string')[3:5])",
+                                   "('a string' == x                    )",
+                                   "('a string'[1:2] == x               )",
+                                   "('a string' + 'b string' == x       )",
+                                   "(('a string' + 'b string')[3:5] == x)"
                                  };
 
       const std::size_t invalid_expr_size = sizeof(invalid_expr) / sizeof(std::string);