diff --git a/src/mame/audio/irem.cpp b/src/mame/audio/irem.cpp
index 20303cb17c3..43cbf08b594 100644
--- a/src/mame/audio/irem.cpp
+++ b/src/mame/audio/irem.cpp
@@ -409,7 +409,7 @@ ADDRESS_MAP_END
 #define USE_FRONTIERS 1
 #define USE_FIXED_STV 1
 
-#include "nl_kidniki.cpp"
+#include "nl_kidniki.inc"
 
 NETLIST_START(kidniki_interface)
 
diff --git a/src/mame/audio/nl_kidniki.cpp b/src/mame/audio/nl_kidniki.inc
similarity index 100%
rename from src/mame/audio/nl_kidniki.cpp
rename to src/mame/audio/nl_kidniki.inc