diff --git a/src/spicelib/parser/inppas4.c b/src/spicelib/parser/inppas4.c
index 8155b0601..3d1a3b660 100644
--- a/src/spicelib/parser/inppas4.c
+++ b/src/spicelib/parser/inppas4.c
@@ -9,6 +9,7 @@ Author: 1985 Thomas L. Quarles
 #include "ngspice/inpmacs.h"
 #include "ngspice/fteext.h"
 #include "ngspice/iferrmsg.h"
+#include "ngspice/cktdefs.h"
 
 #include "inppas4.h"
 #include "inpxx.h"