diff --git a/src/kernel/plane.h b/src/kernel/plane.h
index d8ec176a9..926ffb4e2 100644
--- a/src/kernel/plane.h
+++ b/src/kernel/plane.h
@@ -22,6 +22,7 @@ OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 extern "C" {
 #endif
 
+    struct faction;
     struct region;
     struct faction;
     struct plane;
diff --git a/src/kernel/region.h b/src/kernel/region.h
index 5974fd96c..72496193b 100644
--- a/src/kernel/region.h
+++ b/src/kernel/region.h
@@ -66,6 +66,7 @@ extern "C" {
     struct message_list;
     struct rawmaterial;
     struct item;
+    struct faction;
 
 #define MORALE_TAX_FACTOR 0.005 /* 0.5% tax per point of morale */
 #define MORALE_MAX 10           /* Maximum morale allowed */