diff --git a/src/card.c b/src/card.c
index 84a624b..8eedbca 100644
--- a/src/card.c
+++ b/src/card.c
@@ -1,8 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <malloc.h>
-#include <string.h>
 #include <errno.h>
+
 #include "card.h"
 #include "common.h"
 
@@ -11,7 +11,6 @@ void allocate_card(struct card **card) {
     fprintf(stderr, tty_solitaire_error_message(errno, __FILE__, __LINE__));
     exit(errno);
   }
-
   allocate_frame(&((*card)->frame));
 }
 
@@ -22,24 +21,8 @@ void initialize_card(struct card *card) {
   card->face = NO_FACE;
 }
 
-struct card *duplicate_card(struct card *card) {
-  struct card *new_card;
-
-  allocate_card(&new_card);
-  set_card(new_card,
-           card->value,
-           card->suit,
-           card->face,
-           card->frame->begin_y,
-           card->frame->begin_x);
-
-  return(new_card);
-}
-
 void free_card(struct card *card) {
-  if (card) {
-    free_frame(card->frame);
-  }
+  free_frame(card->frame);
   free(card);
 }
 
@@ -62,3 +45,17 @@ void expose_card(struct card *card) {
 void cover_card(struct card *card) {
   card->face = COVERED;
 }
+
+struct card *duplicate_card(struct card *card) {
+  struct card *new_card;
+
+  allocate_card(&new_card);
+  set_card(new_card,
+           card->value,
+           card->suit,
+           card->face,
+           card->frame->begin_y,
+           card->frame->begin_x);
+
+  return(new_card);
+}
diff --git a/src/card.h b/src/card.h
index 347c442..304761e 100644
--- a/src/card.h
+++ b/src/card.h
@@ -31,10 +31,10 @@ struct card {
 
 void allocate_card(struct card **);
 void initialize_card(struct card *);
-struct card *duplicate_card(struct card *);
 void free_card(struct card *);
 void set_card(struct card *, enum value, enum suit, enum face, int, int);
 void expose_card(struct card *);
 void cover_card(struct card *);
+struct card *duplicate_card(struct card *);
 
 #endif
diff --git a/src/cursor.c b/src/cursor.c
index a1a3fa8..2673007 100644
--- a/src/cursor.c
+++ b/src/cursor.c
@@ -1,34 +1,30 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <malloc.h>
-#include <string.h>
 #include <errno.h>
 #include <ncurses.h>
-#include "display.h"
-#include "game.h"
+
 #include "cursor.h"
+#include "game.h"
 #include "common.h"
 
 void allocate_cursor(struct cursor **cursor) {
   if (!(*cursor = malloc(sizeof(**cursor)))) {
     fprintf(stderr, tty_solitaire_error_message(errno, __FILE__, __LINE__));
     exit(errno);
-  } else {
-    (*cursor)->window = NULL;
   }
+  (*cursor)->window = newwin(1, 1, CURSOR_BEGIN_Y, CURSOR_BEGIN_X);
 }
 
 void initialize_cursor(struct cursor *cursor) {
-  cursor->window = newwin(1, 1, cursor->y, cursor->x);
-  cursor->x = CURSOR_BEGIN_X;
+  mvwin(cursor->window, CURSOR_BEGIN_Y, CURSOR_BEGIN_X);
   cursor->y = CURSOR_BEGIN_Y;
+  cursor->x = CURSOR_BEGIN_X;
   cursor->marked = false;
 }
 
 void free_cursor(struct cursor *cursor) {
-  if (cursor) {
-    delwin(cursor->window);
-  }
+  delwin(cursor->window);
   free(cursor);
 }
 
@@ -88,7 +84,7 @@ void move_cursor(struct cursor *cursor, enum movement movement) {
     }
     break;
   case UP:
-    if (cursor->y > 1) {
+    if (cursor->y > CURSOR_BEGIN_Y) {
       cursor->y = CURSOR_BEGIN_Y;
     }
     break;
diff --git a/src/deck.c b/src/deck.c
index 61ed3f8..bc32207 100644
--- a/src/deck.c
+++ b/src/deck.c
@@ -1,8 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <malloc.h>
-#include <string.h>
 #include <errno.h>
+
 #include "deck.h"
 #include "common.h"
 
@@ -11,13 +11,12 @@ void allocate_deck(struct deck **deck) {
     fprintf(stderr, tty_solitaire_error_message(errno, __FILE__, __LINE__));
     exit(errno);
   }
-
   allocate_stack(&((*deck)->stock));
   allocate_stack(&((*deck)->waste_pile));
-  for (int i = 0; i < 4; i++) {
+  for (int i = 0; i < FOUNDATION_STACKS_NUMBER; i++) {
     allocate_stack(&((*deck)->foundation[i]));
   }
-  for (int i = 0; i < 7; i++) {
+  for (int i = 0; i < MANEUVRE_STACKS_NUMBER; i++) {
     allocate_stack(&((*deck)->maneuvre[i]));
   }
 }
@@ -25,24 +24,22 @@ void allocate_deck(struct deck **deck) {
 void initialize_deck(struct deck *deck) {
   initialize_stack(deck->stock);
   initialize_stack(deck->waste_pile);
-  for (int i = 0; i < 4; i++) {
+  for (int i = 0; i < FOUNDATION_STACKS_NUMBER; i++) {
     initialize_stack(deck->foundation[i]);
   }
-  for (int i = 0; i < 7; i++) {
+  for (int i = 0; i < MANEUVRE_STACKS_NUMBER; i++) {
     initialize_stack(deck->maneuvre[i]);
   }
 }
 
 void free_deck(struct deck *deck) {
-  if (deck) {
-    free_stack(deck->stock);
-    free_stack(deck->waste_pile);
-    for (int i = 0; i < 4; i++) {
-      free_stack(deck->foundation[i]);
-    }
-    for (int i = 0; i < 7; i++) {
-      free_stack(deck->maneuvre[i]);
-    }
+  free_stack(deck->stock);
+  free_stack(deck->waste_pile);
+  for (int i = 0; i < FOUNDATION_STACKS_NUMBER; i++) {
+    free_stack(deck->foundation[i]);
+  }
+  for (int i = 0; i < MANEUVRE_STACKS_NUMBER; i++) {
+    free_stack(deck->maneuvre[i]);
   }
   free(deck);
 }
diff --git a/src/deck.h b/src/deck.h
index ff6789d..c73259e 100644
--- a/src/deck.h
+++ b/src/deck.h
@@ -3,11 +3,14 @@
 
 #include "stack.h"
 
+#define FOUNDATION_STACKS_NUMBER 4
+#define MANEUVRE_STACKS_NUMBER 7
+
 struct deck {
   struct stack *stock;
   struct stack *waste_pile;
-  struct stack *foundation[4];
-  struct stack *maneuvre[7];
+  struct stack *foundation[FOUNDATION_STACKS_NUMBER];
+  struct stack *maneuvre[MANEUVRE_STACKS_NUMBER];
 };
 
 void allocate_deck(struct deck **);
diff --git a/src/display.c b/src/display.c
index 430ec04..8c308c5 100644
--- a/src/display.c
+++ b/src/display.c
@@ -3,8 +3,9 @@
 #include <string.h>
 #include <ncurses.h>
 
-#include "game.h"
 #include "display.h"
+#include "deck.h"
+#include "game.h"
 
 static const char *card_suits[4] = { "\u2666", "\u2660", "\u2665", "\u2663" };
 static const char *card_values[13] = {
@@ -69,6 +70,7 @@ void draw_stack(struct stack *stack) {
       for (struct stack *i = reversed_stack; i; i = i->next) {
         draw_card(i->card);
       }
+      free_stack(reversed_stack);
     } else {
       draw_card(stack->card);
     }
@@ -78,10 +80,10 @@ void draw_stack(struct stack *stack) {
 void draw_deck(struct deck *deck) {
   draw_stack(deck->stock);
   draw_stack(deck->waste_pile);
-  for (int i = 0; i < 4; i++) {
+  for (int i = 0; i < FOUNDATION_STACKS_NUMBER; i++) {
     draw_stack(deck->foundation[i]);
   }
-  for (int i = 0; i < 7; i++) {
+  for (int i = 0; i < MANEUVRE_STACKS_NUMBER; i++) {
     draw_stack(deck->maneuvre[i]);
   }
 }
diff --git a/src/frame.c b/src/frame.c
index 957813e..763f2ec 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -1,8 +1,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <malloc.h>
-#include <string.h>
 #include <errno.h>
+
 #include "frame.h"
 #include "common.h"
 
@@ -19,19 +19,8 @@ void initialize_frame(struct frame *frame) {
   frame->begin_x = 0;
 }
 
-struct frame *duplicate_frame(struct frame *frame) {
-  struct frame *new_frame;
-
-  allocate_frame(&new_frame);
-  set_frame(new_frame, frame->begin_y, frame->begin_x);
-
-  return(new_frame);
-}
-
 void free_frame(struct frame *frame) {
-  if (frame) {
-    delwin(frame->window);
-  }
+  delwin(frame->window);
   free(frame);
 }
 
@@ -40,3 +29,12 @@ void set_frame(struct frame *frame, int begin_y, int begin_x) {
   frame->begin_x = begin_x;
   mvwin(frame->window, begin_y, begin_x);
 }
+
+struct frame *duplicate_frame(struct frame *frame) {
+  struct frame *new_frame;
+
+  allocate_frame(&new_frame);
+  set_frame(new_frame, frame->begin_y, frame->begin_x);
+
+  return(new_frame);
+}
diff --git a/src/frame.h b/src/frame.h
index 08eebb6..59288ba 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -14,8 +14,8 @@ struct frame {
 
 void allocate_frame(struct frame **);
 void initialize_frame(struct frame *);
-struct frame *duplicate_frame(struct frame *);
 void free_frame(struct frame *);
 void set_frame(struct frame *, int, int);
+struct frame *duplicate_frame(struct frame *);
 
 #endif
diff --git a/src/game.c b/src/game.c
index 291f928..b4e2d71 100644
--- a/src/game.c
+++ b/src/game.c
@@ -5,12 +5,16 @@
 #include <time.h>
 #include <assert.h>
 
+#include "game.h"
+#include "card.h"
+#include "stack.h"
+#include "deck.h"
 #include "display.h"
+#include "cursor.h"
 #include "curses.h"
 #include "common.h"
-#include "game.h"
 
-int foundation_begin_x(int x) {
+static int foundation_begin_x(int x) {
   switch (x) {
   case 0: return(FOUNDATION_0_BEGIN_X); break;
   case 1: return(FOUNDATION_1_BEGIN_X); break;
@@ -23,7 +27,7 @@ int foundation_begin_x(int x) {
   }
 }
 
-int maneuvre_begin_x(int x) {
+static int maneuvre_begin_x(int x) {
   switch (x) {
   case 0: return(MANEUVRE_0_BEGIN_X); break;
   case 1: return(MANEUVRE_1_BEGIN_X); break;
@@ -39,21 +43,18 @@ int maneuvre_begin_x(int x) {
   }
 }
 
-bool stock_stack(struct stack *stack) {
-  return(stack && stack->card && stack->card->frame &&
-           (stack->card->frame->begin_y == STOCK_BEGIN_Y) &&
-           (stack->card->frame->begin_x == STOCK_BEGIN_X));
+static bool stock_stack(struct stack *stack) {
+  return((stack->card->frame->begin_y == STOCK_BEGIN_Y) &&
+          (stack->card->frame->begin_x == STOCK_BEGIN_X));
 }
 
-bool waste_pile_stack(struct stack *stack) {
-  return(stack && stack->card && stack->card->frame &&
-           (stack->card->frame->begin_y == WASTE_PILE_BEGIN_Y) &&
+static bool waste_pile_stack(struct stack *stack) {
+  return((stack->card->frame->begin_y == WASTE_PILE_BEGIN_Y) &&
            (stack->card->frame->begin_x == WASTE_PILE_BEGIN_X));
 }
 
-bool foundation_stack(struct stack *stack) {
-  return(stack && stack->card && stack->card->frame &&
-           stack->card->frame->begin_y == FOUNDATION_BEGIN_Y &&
+static bool foundation_stack(struct stack *stack) {
+  return(stack->card->frame->begin_y == FOUNDATION_BEGIN_Y &&
            (stack->card->frame->begin_x == FOUNDATION_0_BEGIN_X ||
               stack->card->frame->begin_x == FOUNDATION_1_BEGIN_X ||
               stack->card->frame->begin_x == FOUNDATION_2_BEGIN_X ||
@@ -61,15 +62,14 @@ bool foundation_stack(struct stack *stack) {
 }
 
 bool maneuvre_stack(struct stack *stack) {
-  return(stack && stack->card && stack->card->frame &&
-          stack->card->frame->begin_y >= MANEUVRE_BEGIN_Y &&
-          (stack->card->frame->begin_x == MANEUVRE_0_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_1_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_2_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_3_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_4_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_5_BEGIN_X ||
-            stack->card->frame->begin_x == MANEUVRE_6_BEGIN_X));
+  return(stack->card->frame->begin_y >= MANEUVRE_BEGIN_Y &&
+           (stack->card->frame->begin_x == MANEUVRE_0_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_1_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_2_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_3_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_4_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_5_BEGIN_X ||
+              stack->card->frame->begin_x == MANEUVRE_6_BEGIN_X));
 }
 
 bool valid_move(struct stack *origin, struct stack *destination) {
@@ -135,20 +135,16 @@ static void shuffle_deck(struct deck *deck) {
     fprintf(stderr, tty_solitaire_error_message(errno, __FILE__, __LINE__));
     exit(errno);
   }
-
   for (int i = 0; i < NUMBER_OF_CARDS; i++) {
     card[i] = pop(&(deck->stock));
   }
-
   srand(time(NULL));
-
   for (int i = 0; i < NUMBER_OF_CARDS - 1; i++) {
     random = i + (rand() % (NUMBER_OF_CARDS) - i);
     tmp = *card[i];
     *card[i] = (*card[random]);
     *card[random] = tmp;
   }
-
   for (int i = 0; i < NUMBER_OF_CARDS; i++) {
     push(&(deck->stock), card[i]);
   }
@@ -182,10 +178,10 @@ void initialize_game() {
   /* Setting initial stacks' coordinates. */
   set_frame(deck->stock->card->frame, STOCK_BEGIN_Y, STOCK_BEGIN_X);
   set_frame(deck->waste_pile->card->frame, WASTE_PILE_BEGIN_Y, WASTE_PILE_BEGIN_X);
-  for (int i = 0; i < 4; i++) {
+  for (int i = 0; i < FOUNDATION_STACKS_NUMBER; i++) {
     set_frame(deck->foundation[i]->card->frame, FOUNDATION_BEGIN_Y, foundation_begin_x(i));
   }
-  for (int i = 0; i < 7; i++) {
+  for (int i = 0; i < MANEUVRE_STACKS_NUMBER; i++) {
     set_frame(deck->maneuvre[i]->card->frame, MANEUVRE_BEGIN_Y, maneuvre_begin_x(i));
   }
 
diff --git a/src/game.h b/src/game.h
index fd714bf..5913ce9 100644
--- a/src/game.h
+++ b/src/game.h
@@ -31,10 +31,8 @@
 struct deck *deck;
 struct cursor *cursor;
 
-int foundation_begin_x(int);
-int maneuvre_begin_x(int);
-bool valid_move(struct stack *, struct stack *);
 bool maneuvre_stack(struct stack *);
+bool valid_move(struct stack *, struct stack *);
 void move_card(struct stack **, struct stack **);
 void greet_player();
 void initialize_game();
diff --git a/src/keyboard.c b/src/keyboard.c
index 970cc58..3661216 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -1,10 +1,12 @@
 #include <stdlib.h>
 #include <assert.h>
 
+#include "keyboard.h"
+#include "stack.h"
 #include "game.h"
+#include "cursor.h"
 #include "display.h"
 #include "curses.h"
-#include "keyboard.h"
 
 static struct stack **cursor_stack(struct cursor *cursor) {
   if (cursor->y == CURSOR_BEGIN_Y) {
@@ -101,6 +103,8 @@ static void handle_card_movement(struct cursor *cursor) {
       break;
     case KEY_SPACEBAR:
       destination = cursor_stack(cursor);
+      /* As 'destination' can be NULL if the cursor is at the invalid spot we
+       * check it before dereferencing */
       if (destination && valid_move(*origin, *destination)) {
         erase_stack(*origin);
         move_card(origin, destination);
diff --git a/src/stack.c b/src/stack.c
index f3b5f99..6d2cde3 100644
--- a/src/stack.c
+++ b/src/stack.c
@@ -2,9 +2,10 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <malloc.h>
-#include <string.h>
 #include <errno.h>
+
 #include "stack.h"
+#include "card.h"
 #include "common.h"
 
 void allocate_stack(struct stack **stack) {
@@ -12,7 +13,6 @@ void allocate_stack(struct stack **stack) {
     fprintf(stderr, tty_solitaire_error_message(errno, __FILE__, __LINE__));
     exit(errno);
   }
-
   allocate_card(&((*stack)->card));
 }
 
@@ -21,6 +21,16 @@ void initialize_stack(struct stack *stack) {
   stack->next = NULL;
 }
 
+void free_stack(struct stack *stack) {
+  struct stack *tmp;
+
+  for (; stack; stack = tmp) {
+    tmp = stack->next;
+    free_card(stack->card);
+    free(stack);
+  }
+}
+
 struct stack *duplicate_stack(struct stack *stack) {
   struct stack *iterator = stack;
   struct stack *tmp_stack, *new_stack;
@@ -40,16 +50,6 @@ struct stack *duplicate_stack(struct stack *stack) {
   return(new_stack);
 }
 
-void free_stack(struct stack *stack) {
-  struct stack *tmp;
-
-  for (; stack; stack = tmp) {
-    tmp = stack->next;
-    free_card(stack->card);
-    free(stack);
-  }
-}
-
 bool empty(struct stack *stack) {
   return(stack->card->value == NO_VALUE &&
            stack->card->suit == NO_SUIT &&
@@ -107,16 +107,21 @@ struct card *pop(struct stack **stack) {
 }
 
 struct stack *reverse(struct stack *stack) {
-  if (length(stack) > 1) {
-    struct stack *tmp_stack, *iterator;
+  struct stack *tmp_stack, *iterator;
 
-    allocate_stack(&tmp_stack);
-    initialize_stack(tmp_stack);
+  allocate_stack(&tmp_stack);
+  initialize_stack(tmp_stack);
+  if (length(stack) > 1) {
     for (iterator = stack; iterator; iterator = iterator->next) {
-      push(&tmp_stack, iterator->card);
+      push(&tmp_stack, duplicate_card(iterator->card));
     }
-    return(tmp_stack);
   } else {
-    return(stack);
+    set_card(tmp_stack->card,
+             stack->card->value,
+             stack->card->suit,
+             stack->card->face,
+             stack->card->frame->begin_y,
+             stack->card->frame->begin_x);
   }
+  return(tmp_stack);
 }
diff --git a/src/stack.h b/src/stack.h
index 395b3ee..8e16cbf 100644
--- a/src/stack.h
+++ b/src/stack.h
@@ -10,8 +10,8 @@ struct stack {
 
 void allocate_stack(struct stack **);
 void initialize_stack(struct stack *);
-struct stack *duplicate_stack(struct stack *);
 void free_stack(struct stack *);
+struct stack *duplicate_stack(struct stack *);
 bool empty(struct stack *);
 int length(struct stack *);
 void push(struct stack **, struct card *);
diff --git a/src/ttysolitaire.c b/src/ttysolitaire.c
index bd7da5c..59f1d65 100644
--- a/src/ttysolitaire.c
+++ b/src/ttysolitaire.c
@@ -1,8 +1,9 @@
 #include <stdlib.h>
 #include <ncurses.h>
-#include "curses.h"
+
 #include "game.h"
 #include "keyboard.h"
+#include "curses.h"
 
 const char *program_name;