--- a/src/mk/commondefs
+++ b/src/mk/commondefs
@@ -3,7 +3,7 @@
 
 COMMONCXXFLAGS = -I. -I$(depth)/index \
 	       -I$(depth)/utils -I$(depth)/common \
-	       -I$(depth)/unac -I$(depth)/bincimapmime \
+	       -I$(depth)/unac -I$(depth)/bincimapmime -I$(depth)/aspell \
 	       -I/usr/local/include
 
 # We happen to be using gcc on all platforms for now. Can be overridden in