diff --git a/CMakeLists.txt b/CMakeLists.txt
index 23897ad..1fcb071 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,7 +27,7 @@ endif()
 
 target_include_directories(csnake PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include)
 
-set(SIZE 10 CACHE STRING "Size of game field")
+set(FIELD_SIZE 10 CACHE STRING "Size of game field")
 set(DEFX 0 CACHE STRING "Start x")
 set(DEFY 0 CACHE STRING "Start y")
 set(SLEEP 1000 CACHE STRING "Sleep between frames (ms)")
diff --git a/configure b/configure
index 58daf1f..24a587a 100755
--- a/configure
+++ b/configure
@@ -3,14 +3,14 @@
 usage()
 {
     echo "Use environment variables to pass values:
-    CC      - compiler (default: cc)
-    CFLAGS  - flags for compiler
-    LDFLAGS - flags for linker
-    OUT     - out file (default: csnake
-    SIZE    - size of game field
-    DEFX    - start x
-    DEFY    - start y
-    SLEEP   - sleep between frames (ms)"
+    CC         - compiler (default: cc)
+    CFLAGS     - flags for compiler
+    LDFLAGS    - flags for linker
+    OUT        - out file (default: csnake
+    FIELD_SIZE - size of game field
+    DEFX       - start x
+    DEFY       - start y
+    SLEEP      - sleep between frames (ms)"
     exit 1
 }
 
@@ -28,7 +28,7 @@ CC=${CC:-cc}
 CFLAGS=${CFLAGS:-}
 LDFLAGS=${LDFLAGS:-}
 OUT=${OUT:-csnake}
-SIZE=${SIZE:-10}
+FIELD_SIZE=${FIELD_SIZE:-10}
 DEFX=${DEFX:-0}
 DEFY=${DEFY:-0}
 SLEEP=${SLEEP:-1000}
@@ -40,7 +40,7 @@ echo "LDFLAGS: $LDFLAGS"
 echo "Out file: $OUT"
 echo
 echo "Code configuration:"
-echo "Size: $SIZE"
+echo "Field size: $FIELD_SIZE"
 echo "Start x: $DEFX"
 echo "Start y: $DEFY"
 echo "Sleep: $SLEEP"
@@ -50,7 +50,7 @@ CFLAGS = $CFLAGS
 LDFLAGS = $LDFLAGS
 OUT = $OUT" > config.mk
 
-echo "#define SIZE $SIZE
+echo "#define FIELD_SIZE $FIELD_SIZE
 #define DEFX $DEFX
 #define DEFY $DEFY
 #define SLEEP $SLEEP" > include/config.h
diff --git a/include/config.h.in b/include/config.h.in
index 6e8c841..2bc5945 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -1,4 +1,4 @@
-#define SIZE ${SIZE}
+#define FIELD_SIZE ${FIELD_SIZE}
 #define DEFX ${DEFX}
 #define DEFY ${DEFY}
 #define SLEEP ${SLEEP}
diff --git a/include/platform/screen.h b/include/platform/screen.h
index 7ee43b0..09a532f 100644
--- a/include/platform/screen.h
+++ b/include/platform/screen.h
@@ -2,7 +2,7 @@
 #define __PLATFORM_SCREEN_H__
 
 #ifdef _WIN32
-#include <Windows.h>
+#include <windows.h>
 #else
 #include <stdio.h>
 #endif /* _WIN32 */
diff --git a/src/main.c b/src/main.c
index 80ccd28..6bbb7ea 100644
--- a/src/main.c
+++ b/src/main.c
@@ -25,7 +25,7 @@ Food generateFood(Player player)
     Food food;
     do
     {
-        food = (Food){rand() % SIZE, rand() % SIZE};
+        food = (Food){rand() % FIELD_SIZE, rand() % FIELD_SIZE};
     } while (playerCheckFoodCollision(player, food));
     return food;
 }
@@ -36,7 +36,7 @@ int main(int argc, char **argv)
     platformGameInit();
 
     Player player; playerCreate(&player, DOWN, DEFX, DEFY, 0);
-    Screen screen; screenCreate(&screen, SIZE, SIZE, ' ');
+    Screen screen; screenCreate(&screen, FIELD_SIZE, FIELD_SIZE, ' ');
     Food   food =  generateFood(player);
 
     int  key = 0;
@@ -53,7 +53,7 @@ int main(int argc, char **argv)
 
         resetCoordinates();
         screenShow(screen);
-        for (int i = 0; i < SIZE*2; ++i) putchar('-');
+        for (int i = 0; i < FIELD_SIZE*2; ++i) putchar('-');
         printf("\nScore: %d\n", player.score);
 
         sleepMS(SLEEP);
@@ -79,12 +79,12 @@ int main(int argc, char **argv)
         } key = 0;
         if (stopped) continue;
 
-        if (playerDoTick(&player, food) && player.score < SIZE*SIZE - 1)
+        if (playerDoTick(&player, food) && player.score < FIELD_SIZE*FIELD_SIZE - 1)
             food = generateFood(player);
 
         head_x = player.head->x;
         head_y = player.head->y;
-        if (head_x >= SIZE || head_x < 0 || head_y >= SIZE || head_y < 0 || playerCheckSelfCollision(player))
+        if (head_x >= FIELD_SIZE || head_x < 0 || head_y >= FIELD_SIZE || head_y < 0 || playerCheckSelfCollision(player))
         {
             running = false;
             break;