--- a/third-party/pjproject/Makefile
+++ b/third-party/pjproject/Makefile
@@ -100,6 +100,7 @@
 	@mv pjproject-$(PJPROJECT_VERSION) source
 	$(ECHO_PREFIX) Applying patches "$(realpath patches)" "$(realpath .)/source"
 	$(CMD_PREFIX) ../apply_patches $(QUIET_CONFIGURE) "$(realpath patches)" "$(realpath .)/source"
+	cd source && autoconf aconfigure.ac >aconfigure
 	-@touch source/.unpacked
 
 source/version.mak: source/.unpacked
