diff --git a/src/env.c b/src/env.c
index 1dc2b10..d68fff4 100644
--- a/src/env.c
+++ b/src/env.c
@@ -72,22 +72,56 @@ struct Environment envForLambda(const Object *params, const Object *arg_forms,
     return env;
 }
 
+// Determine if a given symbol exists in the given environment chain
+//
+// Modifies `env` to the environment that the symbol was found in, only if the
+// symbol was found
+//
+// Returns the index of the symbol in the environment, if found. Otherwise, -1
+int findInEnv(struct Environment **env, const char *name)
+{
+    struct Environment *temp_env = *env;
+    while(temp_env) {
+        for(int i = 0; i < temp_env->size; i++) {
+            if(temp_env->strings[i] == NULL) {
+                break;
+            }
+            if(strcmp(temp_env->strings[i], name) == 0) {
+                *env = temp_env;
+                return i;
+            }
+        }
+        temp_env = temp_env->outer;
+    }
+    return -1;
+}
+
 // TODO Maybe extend environment using a new outer, instead of realloc
 void addToEnv(struct Environment *env, const char *name, const Object obj)
 {
+    // int sym_pos = findInEnv(&env, name);
+    // if(sym_pos != -1) {
+    //     Object o = cloneObject(obj);
+    //     cleanObject(&env->objects[sym_pos]);
+    //     env->objects[sym_pos] = o;
+    //     return;
+    // }
+
     int i;
     struct Environment *temp_env = env;
     while(temp_env) {
         for(i = 0; i < temp_env->size; i++) {
             if(temp_env->strings[i] == NULL) {
+                //printf("Add new object\n");
                 temp_env->strings[i] = calloc(sizeof(char), strlen(name) + 1);
                 strncpy(temp_env->strings[i], name, strlen(name));
                 temp_env->objects[i] = cloneObject(obj);
                 return;
             }
             if(strcmp(temp_env->strings[i], name) == 0) {
+                Object o = cloneObject(obj);
                 cleanObject(&temp_env->objects[i]);
-                temp_env->objects[i] = cloneObject(obj);
+                temp_env->objects[i] = o;
                 return;
             }
         }