diff --git a/include/toolchain.h b/include/toolchain.h
index 88cedb0fb3b..adc8c2c1101 100644
--- a/include/toolchain.h
+++ b/include/toolchain.h
@@ -41,4 +41,18 @@
 #include <toolchain/other.h>
 #endif
 
+/*
+ * Ensure that __BYTE_ORDER__ and related preprocessor definitions are defined,
+ * as these are often used without checking for definition and doing so can
+ * cause unexpected behaviours.
+ */
+#ifndef _LINKER
+#if !defined(__BYTE_ORDER__) || !defined(__ORDER_BIG_ENDIAN__) || \
+    !defined(__ORDER_LITTLE_ENDIAN__)
+
+#error "__BYTE_ORDER__ is not defined"
+
+#endif
+#endif /* !_LINKER */
+
 #endif /* ZEPHYR_INCLUDE_TOOLCHAIN_H_ */