diff --git a/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.cpp b/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.cpp
index da87ce976..9d3adc1ba 100644
--- a/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.cpp
+++ b/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.cpp
@@ -24,12 +24,13 @@
 
 #if HAS_TFT_LVGL_UI
 
+#include "../../../../inc/MarlinConfig.h"
 #include "SPIFlashStorage.h"
 
-uint8_t SPIFlashStorage::::m_pageData[SPI_FLASH_PageSize];
-uint32_t SPIFlashStorage::::m_currentPage;
-uint16_t SPIFlashStorage::::m_pageDataUsed;
-uint32_t SPIFlashStorage::::m_startAddress;
+uint8_t SPIFlashStorage::m_pageData[SPI_FLASH_PageSize];
+uint32_t SPIFlashStorage::m_currentPage;
+uint16_t SPIFlashStorage::m_pageDataUsed;
+uint32_t SPIFlashStorage::m_startAddress;
 
 #if HAS_SPI_FLASH_COMPRESSION
 
@@ -291,7 +292,7 @@ void SPIFlashStorage::beginRead(uint32_t startAddress) {
 
 uint16_t SPIFlashStorage::outData(uint8_t* data, uint16_t size) {
   // Don't read more than we have
-  NOMORE(size > pageDataFree());
+  NOMORE(size, pageDataFree());
   memcpy(data, m_pageData + m_pageDataUsed, size);
   m_pageDataUsed += size;
   return size;
diff --git a/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.h b/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.h
index c806068dd..5a1241370 100644
--- a/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.h
+++ b/Marlin/src/lcd/extui/lib/mks_ui/SPIFlashStorage.h
@@ -79,7 +79,7 @@ public:
   static void endWrite();
   static void writeData(uint8_t* data, uint16_t size);
 
-  static // Read operation
+  // Read operation
   static void beginRead(uint32_t startAddress);
   static void readData(uint8_t* data, uint16_t size);
 
diff --git a/Marlin/src/lcd/extui/lib/mks_ui/pic_manager.cpp b/Marlin/src/lcd/extui/lib/mks_ui/pic_manager.cpp
index 771e3e062..3f87c5183 100644
--- a/Marlin/src/lcd/extui/lib/mks_ui/pic_manager.cpp
+++ b/Marlin/src/lcd/extui/lib/mks_ui/pic_manager.cpp
@@ -482,7 +482,7 @@ uint8_t public_buf[512];
         if (card.longFilename[0] == '.') continue;
 
         int8_t a = arrayFindStr(assets, COUNT(assets), card.longFilename);
-        if (a >= 0 && a < COUNT(assets)) {
+        if (a >= 0 && a < (int8_t)COUNT(assets)) {
           uint8_t assetType = ASSET_TYPE_ICON;
           if (strstr(assets[a], "_logo"))
             assetType = ASSET_TYPE_LOGO;
@@ -498,7 +498,7 @@ uint8_t public_buf[512];
 
         #if HAS_SPI_FLASH_FONT
           a = arrayFindStr(fonts, COUNT(fonts), card.longFilename);
-          if (a >= 0 && a < COUNT(fonts))
+          if (a >= 0 && a < (int8_t)COUNT(fonts))
             loadAsset(dir, d, fonts[a], ASSET_TYPE_FONT);
         #endif
       }