diff --git a/include/etl/hash.h b/include/etl/hash.h
index 0c0385e1..5af439c7 100644
--- a/include/etl/hash.h
+++ b/include/etl/hash.h
@@ -36,6 +36,8 @@ SOFTWARE.
 
 #include "platform.h"
 
+#if ETL_USING_8BIT_TYPES
+
 // The default hash calculation.
 #include "fnv_1.h"
 #include "type_traits.h"
@@ -436,4 +438,6 @@ namespace etl
   };
 }
 
+#endif ETL_USING_8BIT_TYPES
+
 #endif