diff --git a/2021/day-09/Justfile b/2021/day-09/Justfile
index 511a4fd..91d0db5 100644
--- a/2021/day-09/Justfile
+++ b/2021/day-09/Justfile
@@ -1,5 +1,5 @@
 @part PART INPUT_FILE="inputs/puzzle.txt":
-    gcc -std=c17 -Werror -Wextra -o part_{{PART}} common.c part_{{PART}}.c
+    gcc -std=c17 -Werror -Wextra -pedantic -o part_{{PART}} common.c part_{{PART}}.c
     ./part_{{PART}} {{INPUT_FILE}}
 
 clean:
diff --git a/2021/day-09/common.c b/2021/day-09/common.c
index b26eada..23f815c 100644
--- a/2021/day-09/common.c
+++ b/2021/day-09/common.c
@@ -6,7 +6,7 @@
 
 int MAP_WIDTH = 0;
 int MAP_HEIGHT = 0;
-int MAP[100][100];
+int MAP[MAP_MAX_Y][MAP_MAX_X];
 
 void read_file(char* path) {
     FILE* fp = fopen(path, "r");
@@ -37,6 +37,8 @@ void read_file(char* path) {
     }
 
     MAP_HEIGHT = y;
+
+    fclose(fp);
 }
 
 void print_map(int map[100][100]) {
diff --git a/2021/day-09/common.h b/2021/day-09/common.h
index f12a72a..d2eb9c6 100644
--- a/2021/day-09/common.h
+++ b/2021/day-09/common.h
@@ -1,8 +1,10 @@
 #pragma once
 
+#define MAP_MAX_Y 100
+#define MAP_MAX_X 100
 extern int MAP_WIDTH;
 extern int MAP_HEIGHT;
-extern int MAP[100][100];
+extern int MAP[MAP_MAX_Y][MAP_MAX_X];
 
 typedef int (*result_fn)(int, int, int);
 
diff --git a/2021/day-09/part_two.c b/2021/day-09/part_two.c
index f1cbdb7..032f21d 100644
--- a/2021/day-09/part_two.c
+++ b/2021/day-09/part_two.c
@@ -7,7 +7,7 @@
 int BASIN_IDX = 0;
 int BASINS[BASIN_COUNT] = { 0 };
 
-int scout_basin(int x, int y, int marked[100][100]) {
+int scout_basin(int x, int y, int marked[MAP_MAX_Y][MAP_MAX_X]) {
     marked[y][x] = 1;
     int count = 1;
 
@@ -31,7 +31,7 @@ int scout_basin(int x, int y, int marked[100][100]) {
 }
 
 int calculate_basin_size(int x, int y, int cur) {
-    int marked[100][100] = { 0 };
+    int marked[MAP_MAX_Y][MAP_MAX_X] = { 0 };
     int basin_size = scout_basin(x, y, marked);
     BASINS[BASIN_IDX] = basin_size;
     BASIN_IDX++;