diff --git a/book/Makefile b/book/Makefile
index d4b9822..d1e55d2 100644
--- a/book/Makefile
+++ b/book/Makefile
@@ -16,6 +16,7 @@ LYCHEE ?= lychee
 PRINTF ?= printf
 RM ?= rm
 WATCHEXEC ?= watchexec
+ASSETSDIR = assets
 SOURCEDIR     = source
 BUILDDIR      = build
 
@@ -25,7 +26,7 @@ clean-all: clean
 
 # convert all SVG to plain SVGs without metadata and paths instead of text
 convert-svg:
-	for file in $(SOURCEDIR)/../assets/inkscape/*.svg $(SOURCEDIR)/../assets/drawio/*.svg; do if [[ ! -f $(SOURCEDIR)/plain_svg/$$(basename $$file) ]]; then $(INKSCAPE) --export-text-to-path --export-plain-svg --export-filename=$(SOURCEDIR)/plain_svg/$$(basename $$file) $$file; fi; done
+	for file in $(ASSETSDIR)/inkscape/*.svg $(ASSETSDIR)/drawio/*.svg; do if [[ ! -f $(SOURCEDIR)/plain_svg/$$(basename $$file) ]]; then $(INKSCAPE) --export-text-to-path --export-plain-svg --export-filename=$(SOURCEDIR)/plain_svg/$$(basename $$file) $$file; fi; done
 
 epub: convert-svg
 	@$(SPHINXBUILD) -M epub "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)