diff --git a/module/Makefile b/module/Makefile
index 78b395a5..dd037a01 100644
--- a/module/Makefile
+++ b/module/Makefile
@@ -1,7 +1,9 @@
 MODULES = nominatim
-VPATH = $(MODSRCDIR)
+PG_CPPFLAGS = -I$(MODSRCDIR)
 include $(PGXS)
 
+VPATH = $(MODSRCDIR)
+
 all:
 	chmod 755 nominatim.so