diff --git a/make-includes/build_section_rules.make b/make-includes/build_section_rules.make
index c35d149..a2e6767 100755
--- a/make-includes/build_section_rules.make
+++ b/make-includes/build_section_rules.make
@@ -249,7 +249,7 @@
 	@echo $(ANSWER_TEX_INPUTS) > $@
 
 answer-pdfs:
-	@$(foreach d,$(QUESTION_SRC_DIRS),if $(MAKE) -C $d $d-answers.pdf $d-answers-2up.pdf; then /usr/bin/true; else exit 1; fi;)
+	@$(foreach d,$(ANSWER_SRC_DIRS),if $(MAKE) -C $d $d-answers.pdf $d-answers-2up.pdf; then /usr/bin/true; else exit 1; fi;)
 
 
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