diff --git a/docs/design/interrupt-framework-design.rst b/docs/design/interrupt-framework-design.rst
index 6f692b2..d4057ea 100644
--- a/docs/design/interrupt-framework-design.rst
+++ b/docs/design/interrupt-framework-design.rst
@@ -48,7 +48,7 @@
 The following constants define the various interrupt types in the framework
 implementation.
 
-::
+.. code:: c
 
     #define INTR_TYPE_S_EL1      0
     #define INTR_TYPE_EL3        1