diff --git a/compiler/Generator.cs b/compiler/Generator.cs
index b3eab4f..b36bbbe 100644
--- a/compiler/Generator.cs
+++ b/compiler/Generator.cs
@@ -99,6 +99,7 @@ public class Generator
                          #include <stdint.h>
                          #include <stdlib.h>
 
+                         #define FLAG_STRING_LITERAL 1
                          """);
 
         while (referencedTypes.Count != 0)
@@ -131,6 +132,7 @@ public class Generator
                     writer.WriteLine("char *data;");
                     writer.WriteLine("size_t length;");
                     writer.WriteLine("uint32_t ref;");
+                    writer.WriteLine("uint32_t flags;");
                 }
                 writer.WriteLine("};");
                 writer.WriteLine();
@@ -462,6 +464,7 @@ public class Generator
         writer.WriteLine($"{name}->data = \"{expression.Value.Value}\";");
         writer.WriteLine($"{name}->length = {expression.Value.Value.Length};");
         writer.WriteLine($"{name}->ref = 1;");
+        writer.WriteLine($"{name}->flags = FLAG_STRING_LITERAL;");
 
         return name;
     }
@@ -601,6 +604,13 @@ public class Generator
                 writer.WriteLine("{");
                 using (writer.Indent())
                 {
+                    writer.WriteLine($"if (({value}->flags & FLAG_STRING_LITERAL) == 0)");
+                    writer.WriteLine("{");
+                    using (writer.Indent())
+                    {
+                        writer.WriteLine($"free({value}->data);");
+                    }
+                    writer.WriteLine("}");
                     writer.WriteLine($"free({value});");
                 }
                 writer.WriteLine("}");