diff --git a/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_fb.c b/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_fb.c
index 41fd36e433..f23f4f47b9 100644
--- a/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_fb.c
+++ b/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_fb.c
@@ -31,10 +31,10 @@
 
 // Physical frame buffers in internal SRAM memory
 __attribute__((section(".fb1")))
-ALIGN_32BYTES(uint32_t physical_frame_buffer_0[PHYSICAL_FRAME_BUFFER_SIZE]);
+ALIGN_32BYTES(uint8_t physical_frame_buffer_0[PHYSICAL_FRAME_BUFFER_SIZE]);
 
 __attribute__((section(".fb2")))
-ALIGN_32BYTES(uint32_t physical_frame_buffer_1[PHYSICAL_FRAME_BUFFER_SIZE]);
+ALIGN_32BYTES(uint8_t physical_frame_buffer_1[PHYSICAL_FRAME_BUFFER_SIZE]);
 
 // The current frame buffer selector at fixed memory address
 // It's shared between bootloaders and the firmware
diff --git a/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_internal.h b/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_internal.h
index af6e543c89..fb80a01720 100644
--- a/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_internal.h
+++ b/core/embed/trezorhal/stm32u5/xdisplay/stm32u5a9j-dk/display_internal.h
@@ -40,7 +40,7 @@ extern display_driver_t g_display_driver;
 //
 // It's smaller than size of the virtual frame buffer
 // due to used GFXMMU settings
-#define PHYSICAL_FRAME_BUFFER_SIZE 184320
+#define PHYSICAL_FRAME_BUFFER_SIZE (184320 * 4)
 
 // Pitch (in pixels) of the virtual frame buffer
 #define FRAME_BUFFER_PIXELS_PER_LINE 768
@@ -53,8 +53,8 @@ extern display_driver_t g_display_driver;
 //
 // Both frame buffers layes in the fixed addresses that
 // are shared between bootloaders and the firmware.
-extern uint32_t physical_frame_buffer_0[PHYSICAL_FRAME_BUFFER_SIZE];
-extern uint32_t physical_frame_buffer_1[PHYSICAL_FRAME_BUFFER_SIZE];
+extern uint8_t physical_frame_buffer_0[PHYSICAL_FRAME_BUFFER_SIZE];
+extern uint8_t physical_frame_buffer_1[PHYSICAL_FRAME_BUFFER_SIZE];
 
 // The current frame buffer selector at fixed memory address
 //