diff --git a/src/images.c b/src/images.c
index a02870e..4619419 100644
--- a/src/images.c
+++ b/src/images.c
@@ -4,7 +4,7 @@
 #include "images.h"
 
 
-int image_new(int width, int height, Image* img) {
+int image_new(unsigned int width, unsigned int height, Image* img) {
     //Image img = malloc(sizeof(Image));
 
     if (img == NULL) return 0;
@@ -20,7 +20,7 @@ int image_new(int width, int height, Image* img) {
 
     // initialize bitmap...
     img->bitmap = malloc(height * sizeof(char*));
-    for (int i = 0; i < height; i++) {
+    for (unsigned int i = 0; i < height; i++) {
         img->bitmap[i] = malloc(3 * width * sizeof(char));
     }
 
@@ -28,7 +28,7 @@ int image_new(int width, int height, Image* img) {
     return 1;
 }
 
-int image_set_px(Image image, int x, int y, int r, int g, int b) {
+int image_set_px(Image image, unsigned int x, unsigned int y, int r, int g, int b) {
     if (!image_check_coords(image, x, y)) return 0;
 
     image.bitmap[y][(3 * x) + 0] = r;
@@ -37,7 +37,7 @@ int image_set_px(Image image, int x, int y, int r, int g, int b) {
 
     return 1;
 }
-int image_set_px_c(Image image, int x, int y, Color color) {
+int image_set_px_c(Image image, unsigned int x, unsigned int y, Color color) {
     if (!image_check_coords(image, x, y)) return 0;
 
     if (color.alpha == 0) return 1;
@@ -55,7 +55,7 @@ int image_set_px_c(Image image, int x, int y, Color color) {
     return 1;
 }
 
-int image_check_coords(Image image, int x, int y) {
+int image_check_coords(Image image, unsigned int x, unsigned int y) {
     return x >= 0 && x < image.width && 
            y >= 0 && y < image.height;
 }
diff --git a/src/images.h b/src/images.h
index dcd628f..c877b72 100644
--- a/src/images.h
+++ b/src/images.h
@@ -11,17 +11,17 @@ typedef struct _color {
 
 typedef struct _image {
     unsigned char** bitmap;
-    int width;
-    int height;
+    unsigned int width;
+    unsigned int height;
 } Image;
 
 // basic image manipulation (src/images.c)
-int image_new(int width, int height, Image* image);
+int image_new(unsigned int width, unsigned int height, Image* image);
 
-int image_set_px(Image image, int x, int y, int r, int g, int b);
-int image_set_px_c(Image image, int x, int y, Color color);
+int image_set_px(Image image, unsigned int x, unsigned int y, int r, int g, int b);
+int image_set_px_c(Image image, unsigned int x, unsigned int y, Color color);
 
-int image_check_coords(Image image, int x, int y);
+int image_check_coords(Image image, unsigned int x, unsigned int y);
 
 int image_destroy(Image image);
 
diff --git a/src/multithreading.c b/src/multithreading.c
index c5cca94..e7b1166 100644
--- a/src/multithreading.c
+++ b/src/multithreading.c
@@ -22,7 +22,7 @@ int image_new_shared(int width, int height, Image* img) {
 }
 
 void image_destroy_shared(Image img) {
-    for (int i = 0; i < img.height; i++) {
+    for (unsigned int i = 0; i < img.height; i++) {
         munmap(img.bitmap[i], 3 * img.width * sizeof(char));
     }  
     munmap(img.bitmap, img.height * sizeof(char*));