diff --git a/lib/sdk11/components/libraries/bootloader_dfu/dfu_dual_bank.c b/lib/sdk11/components/libraries/bootloader_dfu/dfu_dual_bank.c
index 99f3d45..c98e229 100644
--- a/lib/sdk11/components/libraries/bootloader_dfu/dfu_dual_bank.c
+++ b/lib/sdk11/components/libraries/bootloader_dfu/dfu_dual_bank.c
@@ -817,6 +817,9 @@ uint32_t dfu_sd_image_validate(void)
         uint32_t image_end       = bootloader_settings.sd_image_start + 
                                    bootloader_settings.sd_image_size;
 
+        /* ##### FIX START ##### */
+        block_size &= ~(uint32_t)(CODE_PAGE_SIZE - 1); 
+        /* ##### FIX END ##### */       
         uint32_t img_block_start = bootloader_settings.sd_image_start + 2 * block_size;
         uint32_t sd_block_start  = sd_start + 2 * block_size;