diff --git a/kitty/line.h b/kitty/line.h
index 580f521f3..bae95b910 100644
--- a/kitty/line.h
+++ b/kitty/line.h
@@ -44,6 +44,10 @@ typedef struct {
 } GPUCell;
 static_assert(sizeof(GPUCell) == 20, "Fix the ordering of GPUCell");
 
+#define SCALE_BITS 3
+#define WIDTH_BITS 3
+#define SUBSCALE_BITS 4
+
 typedef union CPUCell {
     struct {
         char_type ch_or_idx: sizeof(char_type) * 8 - 1;
@@ -52,12 +56,12 @@ typedef union CPUCell {
         char_type next_char_was_wrapped : 1;
         char_type is_multicell : 1;
         char_type natural_width: 1;
-        char_type x : 8;
-        char_type y : 4;
-        char_type subscale_n: 4;
-        char_type subscale_d: 4;
-        char_type scale: 3;
-        char_type width: 3;
+        char_type x : WIDTH_BITS + SCALE_BITS + 1;
+        char_type y : SCALE_BITS + 1;
+        char_type subscale_n: SUBSCALE_BITS;
+        char_type subscale_d: SUBSCALE_BITS;
+        char_type scale: SCALE_BITS;
+        char_type width: WIDTH_BITS;
         char_type vertical_align: 3;
         char_type : 15;
     };
diff --git a/kitty/screen.c b/kitty/screen.c
index 44daf3364..d018d3068 100644
--- a/kitty/screen.c
+++ b/kitty/screen.c
@@ -1209,8 +1209,9 @@ screen_handle_multicell_command(Screen *self, const MultiCellCommand *cmd, const
     self->lc->count = decode_utf8_safe_string(payload, cmd->payload_sz, self->lc->chars);
     if (!self->lc->count) return;
     CPUCell mcd = {
-        .width=MIN(cmd->width, 15u), .scale=MAX(1u, MIN(cmd->scale, 15u)), .subscale_n=MIN(cmd->subscale_n, 15u),
-        .subscale_d=MIN(cmd->subscale_d, 15u), .vertical_align=MIN(cmd->vertical_align, 7u), .is_multicell=true
+        .width=MIN(cmd->width, (WIDTH_BITS << 1) - 1), .scale=MAX(1u, MIN(cmd->scale, (SCALE_BITS << 1) - 1)),
+        .subscale_n=MIN(cmd->subscale_n, (SUBSCALE_BITS << 1) - 1), .subscale_d=MIN(cmd->subscale_d, (SUBSCALE_BITS << 1) - 1),
+        .vertical_align=MIN(cmd->vertical_align, 7u), .is_multicell=true
     };
     if (mcd.width) handle_fixed_width_multicell_command(self, mcd, self->lc);
     else {