diff --git a/src/evaluate.c b/src/evaluate.c
index b2bf64b..27f462c 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -40,13 +40,10 @@ struct ucl_object *ucl_evaluate_builtin_form(struct ucl_scope *scope, struct ucl
         assert(0);
     }
 
-    // TODO: cleanup
-
     return (result == NULL) ? ucl_nil_create() : result;
 }
 
 struct ucl_object *ucl_evaluate_special_form(struct ucl_scope *scope, struct ucl_object *list) {
-    // TODO: Recursively eval args
     const char *fun_sym = ucl_car(list)->symbol;
 
     struct ucl_object *fun = ucl_scope_get(scope, fun_sym);
@@ -72,7 +69,6 @@ struct ucl_object *ucl_evaluate_list(struct ucl_scope *scope, struct ucl_object
         return ucl_evaluate_builtin_form(scope, list);
     } else {
         assert(0);
-        // TODO: Lisp functions and other errors
     }
 }
 
diff --git a/src/internal.h b/src/internal.h
index ec36301..4f70f83 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -15,7 +15,6 @@
 
 // TODO: Refactor this struct's location
 struct ucl_scope {
-    // TODO: For garbage collection, we need references from the parent->child state
     struct ucl_object *list;
     struct ucl_scope *parent;
 };
diff --git a/src/main.c b/src/main.c
index bc7dcc9..2889ec1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -67,7 +67,6 @@ int main(int argc, const char **argv) {
 
     // TODO:
     //   - reduce
-    //   - booleans (e.g. not)
 
     if (argc < 2) {
         while (1) {
diff --git a/src/memory.c b/src/memory.c
index e21d11b..89ca42b 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -122,7 +122,7 @@ void ucl_object_delete(struct ucl_object *obj) {
     ucl_arena_put(object_arena, obj);
 }
 
-void ucl_object_mark(struct ucl_object *obj) {
+static void ucl_object_mark(struct ucl_object *obj) {
     if (obj == NULL || obj->reachable) {
         return;
     }
@@ -134,34 +134,45 @@ void ucl_object_mark(struct ucl_object *obj) {
     }
 }
 
-void ucl_scope_mark(struct ucl_arena * arena, void *obj) {
+static void ucl_scope_mark(struct ucl_arena * arena, void *obj) {
     (void) arena;
     struct ucl_scope *scope = (struct ucl_scope *) obj;
 
     ucl_object_mark(scope->list);
 }
 
-void ucl_gc_unmark(struct ucl_arena * arena, void *obj) {
+static void ucl_gc_unmark(struct ucl_arena * arena, void *obj) {
     (void) arena;
     struct ucl_object *object = (struct ucl_object *) obj;
     object->reachable = 0;
 }
 
-void ucl_gc_sweep(struct ucl_arena * arena, void *obj) {
+static void ucl_gc_sweep(struct ucl_arena * arena, void *obj) {
     (void) arena;
     struct ucl_object *object = (struct ucl_object *) obj;
     if (object->reachable == 0) {
-        // TODO: Mapping across this is broken, since this is a recursive delete
-        ucl_object_delete(object);
+         ucl_object_delete(object);
     }
 }
 
+static void ucl_gc_deleteall(struct ucl_arena * arena, void *obj) {
+    (void) arena;
+    struct ucl_object *object = (struct ucl_object *) obj;
+    ucl_object_delete(object);
+}
 
 
 void ucl_gc() {
-    ucl_arena_map(object_arena, ucl_gc_unmark);
+    if (object_arena == NULL) {
+        return;
+    }
 
-    ucl_arena_map(scope_arena, ucl_scope_mark);
+    if (scope_arena != NULL) {
+        ucl_arena_map(object_arena, ucl_gc_unmark);
+        ucl_arena_map(scope_arena, ucl_scope_mark);
+        ucl_arena_map(object_arena, ucl_gc_sweep);
+    } else {
+        ucl_arena_map(object_arena, ucl_gc_deleteall);
+    }
 
-    ucl_arena_map(object_arena, ucl_gc_sweep);
 }
diff --git a/src/special.c b/src/special.c
index afcf1fb..170321b 100644
--- a/src/special.c
+++ b/src/special.c
@@ -21,7 +21,6 @@ struct ucl_object *ucl_special_let(struct ucl_scope *scope, struct ucl_object *a
         //assert(ucl_list_length(expr)->integer == 1);
 
         if (value->type == UCL_TYPE_ERROR) {
-            // TODO cleanup
             ucl_scope_delete(let_scope);
             return value;
         }
diff --git a/test/test_e2e.c b/test/test_e2e.c
index 2eca5ca..8f29304 100644
--- a/test/test_e2e.c
+++ b/test/test_e2e.c
@@ -34,11 +34,10 @@ void setUp(void) {
 }
 
 void tearDown(void) {
-    // TODO: Implement GC so we can clean these both up
-    //ucl_object_delete(input);
-    input = NULL;
     ucl_scope_delete(scope);
     ucl_gc();
+
+    input = NULL;
     response = NULL;
     scope = NULL;
 }
diff --git a/test/test_parse.c b/test/test_parse.c
index 5b05fb4..fe74e17 100644
--- a/test/test_parse.c
+++ b/test/test_parse.c
@@ -13,7 +13,8 @@ void setUp(void) {
 }
 
 void tearDown(void) {
-    ucl_object_delete(response);
+    ucl_gc();
+    response = NULL;
 }
 
 static void test_token_next_empty_str(void) {
diff --git a/test/test_scope.c b/test/test_scope.c
index bc7cb52..a329f8b 100644
--- a/test/test_scope.c
+++ b/test/test_scope.c
@@ -18,6 +18,7 @@ void setUp(void) {
 
 void tearDown(void) {
     ucl_scope_delete(scope);
+    ucl_gc();
     scope = NULL;
 }
 
diff --git a/test/test_utility.c b/test/test_utility.c
index 819e6a7..aa9ad18 100644
--- a/test/test_utility.c
+++ b/test/test_utility.c
@@ -17,10 +17,9 @@ void setUp(void) {
 }
 
 void tearDown(void) {
-    // TODO: Implement GC so we can clean these both up
-    //ucl_object_delete(input);
+    ucl_gc();
+
     input = NULL;
-    ucl_object_delete(response);
     response = NULL;
 }