diff --git a/Lib/ufb/Src/framebuffer.c b/Lib/ufb/Src/framebuffer.c
index b4ca56f..5edbfda 100644
--- a/Lib/ufb/Src/framebuffer.c
+++ b/Lib/ufb/Src/framebuffer.c
@@ -57,7 +57,7 @@ void fb_px(fbpos_t x, fbpos_t y, fbcolor_t color)
 
 uint8_t fb_getpx(fbpos_t x, fbpos_t y)
 {
-    if (x >= FBW || y >= FBH) { return 0; }
+    if (x >= FBW || y >= FBH || x < 0 || y < 0) { return 0; }
     const fbpos_t row = y / 8;
     const fbpos_t rowrem = y % 8;
     const fbsize_t cell = (fbsize_t) x + (fbsize_t) row * FBW;
@@ -70,7 +70,7 @@ uint8_t fb_getpx(fbpos_t x, fbpos_t y)
 
 void fb_hline(fbpos_t x, fbpos_t y, fbpos_t w, fbcolor_t color)
 {
-    if (x >= FBW || y >= FBH) { return; }
+    if (x >= FBW || y >= FBH || x < -w || y < 0) { return; }
     w = MIN(FBW - x, w);
     const fbpos_t row = y / 8;
     const fbpos_t rowrem = y % 8;
@@ -83,7 +83,7 @@ void fb_hline(fbpos_t x, fbpos_t y, fbpos_t w, fbcolor_t color)
 
 void fb_vline(fbpos_t x, fbpos_t y, fbpos_t h, fbcolor_t color)
 {
-    if (x >= FBW || y >= FBH) { return; }
+    if (x >= FBW || y >= FBH || x < 0 || y < -h) { return; }
     h = MIN(FBH - y - 1, h);
     const fbpos_t row = y / 8;
     const fbpos_t rowrem = y % 8;
@@ -116,7 +116,7 @@ void fb_vline(fbpos_t x, fbpos_t y, fbpos_t h, fbcolor_t color)
 
 void fb_rect(fbpos_t x, fbpos_t y, fbpos_t w, fbpos_t h, fbcolor_t color)
 {
-    if (x >= FBW || y >= FBH) { return; }
+    if (x >= FBW || y >= FBH || x < -w || y < -h) { return; }
     w = MIN(FBW - x, w);
     h = MIN(FBH - y, h);
     const fbpos_t row = y / 8;
@@ -235,7 +235,7 @@ void fb_bitmap_ex_P(fbpos_t x, fbpos_t y, fbpos_t w, fbpos_t h, const uint8_t *m
 void fb_bitmap_ex(fbpos_t x, fbpos_t y, fbpos_t w, fbpos_t h, const uint8_t *map, fbcolor_t color)
 #endif
 {
-    if (x >= FBW || y >= FBH) { return; }
+    if (x >= FBW || y >= FBH || x < -w || h < -h) { return; }
     const fbpos_t w0 = w;
     w = MIN(FBW - x - 1, w);
     h = MIN(FBH - y - 1, h);