diff --git a/Makefile b/Makefile
index 2628709..0edbaa2 100755
--- a/Makefile
+++ b/Makefile
@@ -213,7 +213,7 @@ build-docs: build-docs-pdf build-docs-html  ## build only docs as PDF and HTML
 
 build-slides: build-slides-pdf build-slides-html  ## build only slides as PDF and HTML
 
-build-slides-pptx: $(SLIDES_PPTX_ALL) $(SLIDES_PPTX_ALL)  ## build PDF slides only
+build-slides-pptx: $(SLIDES_PPTX_ALL) $(SLIDES_MD_ALL)  ## build PPTX slides only
 
 build-slides-pdf: $(SLIDES_PDF_ALL) $(SLIDES_MD_ALL)  ## build PDF slides only