diff --git a/make/projects.mk b/make/projects.mk
index 1ad3fd0e..3791b409 100644
--- a/make/projects.mk
+++ b/make/projects.mk
@@ -19,7 +19,9 @@ MOD_SCRIPT_DIR        ?= $(firstword $(wildcard $(MODDIR)/scripts $(MODDIR)/bin)
 
 # -- Query the build system about other projects:
 PYTHON                ?= /usr/bin/python2
+ifneq ($(TOPDIR),)
 proj_query_cmd         = $(PYTHON) $(MOD_SCRIPT_DIR)/projects.py -p $(PRJS_DIR) -t $(TOPDIR) $(PROJECTS_PY_EXTRA_ARGS)
 proj_query             = $(shell $(proj_query_cmd) $(1))
 proj_dir               = $(call proj_query,proj-dir $(1))
 htdocs_dir             = $(call proj_query,htdocs-dir $(1))
+endif