diff --git a/arch/arm/include/asm/u-boot.h b/arch/arm/include/asm/u-boot.h
index 43cc494..ae4c21b 100644
--- a/arch/arm/include/asm/u-boot.h
+++ b/arch/arm/include/asm/u-boot.h
@@ -49,4 +49,8 @@
 #define IH_ARCH_DEFAULT IH_ARCH_ARM64
 #endif
 
+#if defined(CONFIG_USE_PRIVATE_LIBGCC) && defined(CONFIG_SYS_THUMB_BUILD)
+#error Thumb build does not work with private libgcc.
+#endif
+
 #endif	/* _U_BOOT_H_ */