diff --git a/doc/source/conf.py b/doc/source/conf.py
index 17dbbe6..71d3a95 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -65,6 +65,9 @@ html_static_path = ['_static']
 breathe_projects = {
 	"Reflow Controller Firmware": "../build/_doxygen/xml/"
 }
+
+breathe_domain_by_extension = { "h" : "c",
+				"c" : "c" }
 breathe_default_project = "Reflow Controller Firmware"
 breathe_default_members = ('members', 'undoc-members')