diff --git a/c.nanorc b/c.nanorc
index da8f304..1b201de 100644
--- a/c.nanorc
+++ b/c.nanorc
@@ -1,6 +1,6 @@
 ## Here is an example for C/C++.
 ##
-syntax "c" "\.(c(c|pp|xx)?|C)$" "\.(h(h|pp|xx)?|H)$" "\.ii?$"
+syntax "c" "\.(c(c|pp|xx)?|C)$" "\.(h(h|pp|xx)?|H)$" "\.ii?$" "\.(def)$"
 color brightred "\<[A-Z_][0-9A-Z_]+\>" 
 color green "\<(float|double|bool|char|int|short|long|sizeof|enum|void|static|const|struct|union|typedef|extern|(un)?signed|inline)\>"
 color green "\<((s?size)|((u_?)?int(8|16|32|64|ptr)))_t\>"