diff --git a/include/ns16550.h b/include/ns16550.h
index f45fc8cecc..243226fc3d 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -34,12 +34,10 @@
 #define CONFIG_SYS_NS16550_REG_SIZE (-1)
 #endif
 
-#ifdef CONFIG_NS16550_DYNAMIC
+#if defined(CONFIG_NS16550_DYNAMIC) || defined(CONFIG_DEBUG_UART)
 #define UART_REG(x)	unsigned char x
 #else
-#if defined(CONFIG_SYS_NS16550_MEM32) && !CONFIG_IS_ENABLED(DM_SERIAL)
-#define UART_REG(x) u32 x
-#elif !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
+#if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
 #error "Please define NS16550 registers size."
 #elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
 #define UART_REG(x)						   \