diff --git a/src/game.c b/src/game.c
index fefb0bd..0fcc077 100644
--- a/src/game.c
+++ b/src/game.c
@@ -162,6 +162,7 @@ static void shuffle_deck(struct deck *deck) {
   for (int i = 0; i < NUMBER_OF_CARDS; i++) {
     stack_push(&(deck->stock), card[i]);
   }
+  free(card);
 }
 
 static void deal_cards(struct deck *deck) {
diff --git a/src/stack.c b/src/stack.c
index 9d05556..8a2bd3f 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -69,6 +69,7 @@ int stack_length(struct stack *stack) {
 void stack_push(struct stack **stack, struct card *card) {
   if (card) {
     if (stack_empty(*stack)) {
+      card_free((*stack)->card);
       (*stack)->card = card;
     } else {
       /* Allocating by hand because stack_malloc() would
diff --git a/tests/card_test.c b/tests/card_test.c
index c5abb40..2775cf7 100644
--- a/tests/card_test.c
+++ b/tests/card_test.c
@@ -25,6 +25,9 @@ void test_card_dup() {
 
   assert(card_0 != card_1);
   assert(cards_equal(card_0, card_1));
+
+  card_free(card_0);
+  card_free(card_1);
 }
 
 void test_card_set() {
diff --git a/tests/frame_test.c b/tests/frame_test.c
index fecae56..1a32c35 100644
--- a/tests/frame_test.c
+++ b/tests/frame_test.c
@@ -25,6 +25,9 @@ void test_frame_dup() {
 
   assert(frame_0 != frame_1);
   assert(frames_equal(frame_0, frame_1));
+
+  frame_free(frame_0);
+  frame_free(frame_1);
 }
 
 void test_frame_set() {
diff --git a/tests/game_test.c b/tests/game_test.c
index e38e138..f2fc88b 100644
--- a/tests/game_test.c
+++ b/tests/game_test.c
@@ -406,6 +406,8 @@ void test_move_card_from_stack_empty_stack_to_stack_empty_stack() {
   assert(destination == new_destination);
   assert(stacks_equal(destination, destination_duplicate));
 
+  stack_free(origin_duplicate);
+  stack_free(destination_duplicate);
   stack_free(origin);
   stack_free(destination);
 }
@@ -436,6 +438,8 @@ void test_move_card_from_stack_empty_stack_to_non_stack_empty_stack() {
   assert(destination == new_destination);
   assert(stacks_equal(destination, destination_duplicate));
 
+  stack_free(origin_duplicate);
+  stack_free(destination_duplicate);
   stack_free(origin);
   stack_free(destination);
 }
diff --git a/tests/stack_test.c b/tests/stack_test.c
index 9776af3..9f3434a 100644
--- a/tests/stack_test.c
+++ b/tests/stack_test.c
@@ -30,6 +30,9 @@ void test_stack_dup() {
 
   assert(stack_0 != stack_1);
   assert(stacks_equal(stack_0, stack_1));
+
+  stack_free(stack_0);
+  stack_free(stack_1);
 }
 
 void test_stack_empty_on_stack_empty_stack() {
@@ -185,6 +188,7 @@ void test_stack_pop_on_stack_with_one_element() {
   assert(stack_popped_card == card);
 
   stack_free(stack);
+  card_free(stack_popped_card);
 }
 
 void test_stack_pop_on_stack_with_more_than_one_element() {
@@ -207,6 +211,7 @@ void test_stack_pop_on_stack_with_more_than_one_element() {
   assert(stack_popped_card == card[2]);
 
   stack_free(stack);
+  card_free(stack_popped_card);
 }
 
 void test_stack_reverse_on_stack_empty_stack() {
@@ -220,6 +225,7 @@ void test_stack_reverse_on_stack_empty_stack() {
   assert(stacks_equal(stack_reversed_stack, old_stack));
 
   stack_free(stack);
+  stack_free(stack_reversed_stack);
 }
 
 void test_stack_reverse_on_stack_with_one_element() {
@@ -238,6 +244,7 @@ void test_stack_reverse_on_stack_with_one_element() {
 
   assert(stacks_equal(stack_reversed_stack, old_stack));
 
+  stack_free(stack_reversed_stack);
   stack_free(stack);
 }
 
@@ -264,12 +271,14 @@ void test_stack_reverse_on_stack_with_more_than_one_element() {
 
   assert(stacks_equal(unstack_reversed_stack, old_stack));
 
+  stack_free(unstack_reversed_stack);
   stack_free(stack_reversed_stack);
+  stack_free(old_stack);
   stack_free(stack);
 }
 
 void test_stack_reverse_should_not_change_stack() {
-  struct stack *stack, *old_stack, *old_stack_address;
+  struct stack *stack, *stack_reversed_stack_0, *stack_reversed_stack_1;
   struct card *card[3];
 
   stack_malloc(&stack);
@@ -280,13 +289,14 @@ void test_stack_reverse_should_not_change_stack() {
     card_set(card[i], TWO + i, DIAMONDS + i, EXPOSED, 0, 0);
     stack_push(&stack, card[i]);
   }
-  old_stack_address = stack;
-  old_stack = stack_dup(stack);
-  stack_reverse(stack);
+  stack_reversed_stack_0 = stack_reverse(stack);
+  stack_reversed_stack_1 = stack_reverse(stack_reversed_stack_0);
 
-  assert(stack == old_stack_address);
-  assert(stacks_equal(stack, old_stack));
+  assert(!stacks_equal(stack, stack_reversed_stack_0));
+  assert(stacks_equal(stack, stack_reversed_stack_1));
 
+  stack_free(stack_reversed_stack_0);
+  stack_free(stack_reversed_stack_1);
   stack_free(stack);
 }
 
diff --git a/tests/test_helper_test.c b/tests/test_helper_test.c
index a16921a..accbba7 100644
--- a/tests/test_helper_test.c
+++ b/tests/test_helper_test.c
@@ -11,6 +11,8 @@ void test_frames_equal_with_one_null() {
   frame_malloc(&frame);
   assert(!frames_equal(frame, NULL));
   assert(!frames_equal(NULL, frame));
+
+  frame_free(frame);
 }
 
 void test_frames_equal_with_two_equivalent_frames() {
@@ -23,14 +25,20 @@ void test_frames_equal_with_two_equivalent_frames() {
   frame_set(frame_1, begin_y, begin_x);
 
   assert(frames_equal(frame_0, frame_1));
+
+  frame_free(frame_0);
+  frame_free(frame_1);
 }
 
 void test_frames_equal_with_two_frame_pointers_to_the_same_address() {
   struct frame *frame;
 
   frame_malloc(&frame);
+  frame_init(frame);
 
   assert(frames_equal(frame, frame));
+
+  frame_free(frame);
 }
 
 void test_cards_equal_with_two_nulls() {
@@ -55,14 +63,20 @@ void test_cards_equal_with_two_equivalent_cards() {
   card_set(card_1, ACE, SPADES, EXPOSED, begin_y, begin_x);
 
   assert(cards_equal(card_0, card_1));
+
+  card_free(card_0);
+  card_free(card_1);
 }
 
 void test_cards_equal_with_two_card_pointers_to_the_same_address() {
   struct card *card;
 
   card_malloc(&card);
+  card_init(card);
 
   assert(cards_equal(card, card));
+
+  card_free(card);
 }
 
 void test_stacks_equal_with_two_nulls() {
@@ -73,8 +87,12 @@ void test_stacks_equal_with_one_null() {
   struct stack *stack;
 
   stack_malloc(&stack);
+  stack_init(stack);
+
   assert(!stacks_equal(stack, NULL));
   assert(!stacks_equal(NULL, stack));
+
+  stack_free(stack);
 }
 
 void test_stacks_equal_with_two_equivalent_stacks() {
@@ -88,10 +106,15 @@ void test_stacks_equal_with_two_equivalent_stacks() {
   card_set(card_1, ACE, SPADES, EXPOSED, begin_y, begin_x);
   stack_malloc(&stack_0);
   stack_malloc(&stack_1);
+  stack_init(stack_0);
+  stack_init(stack_1);
   stack_push(&stack_0, card_0);
   stack_push(&stack_1, card_1);
 
   assert(stacks_equal(stack_0, stack_1));
+
+  stack_free(stack_0);
+  stack_free(stack_1);
 }
 
 void test_stacks_equal_with_two_different_stacks() {
@@ -105,18 +128,26 @@ void test_stacks_equal_with_two_different_stacks() {
   card_set(card_1, KING, HEARTS, EXPOSED, begin_y, begin_x);
   stack_malloc(&stack_0);
   stack_malloc(&stack_1);
+  stack_init(stack_0);
+  stack_init(stack_1);
   stack_push(&stack_0, card_0);
   stack_push(&stack_1, card_1);
 
   assert(!stacks_equal(stack_0, stack_1));
+
+  stack_free(stack_0);
+  stack_free(stack_1);
 }
 
 void test_stacks_equal_with_two_stack_pointers_to_the_same_address() {
   struct stack *stack;
 
   stack_malloc(&stack);
+  stack_init(stack);
 
   assert(stacks_equal(stack, stack));
+
+  stack_free(stack);
 }
 
 void test_test_helper() {