diff --git a/Makefile b/Makefile
index c6bc38c..ba7b683 100644
--- a/Makefile
+++ b/Makefile
@@ -14,30 +14,30 @@ CSS_ARG = --css=$(CSS_FILE)
 METADATA_ARG = --metadata-file=$(METADATA)
 ARGS = $(TOC) $(MATH_FORMULAS) $(CSS_ARG) $(METADATA_ARG)
 
-all: book
+all:	book
 
-book: epub html pdf
+book:	epub html pdf
 
 clean:
-  rm -r $(BUILD)
+	rm -r $(BUILD)
 
-epub: $(BUILD)/epub/$(OUTPUT_FILENAME).epub
+epub:	$(BUILD)/epub/$(OUTPUT_FILENAME).epub
 
-html: $(BUILD)/html/$(OUTPUT_FILENAME).html
+html:	$(BUILD)/html/$(OUTPUT_FILENAME).html
 
-pdf: $(BUILD)/pdf/$(OUTPUT_FILENAME).pdf
+pdf:	$(BUILD)/pdf/$(OUTPUT_FILENAME).pdf
 
-$(BUILD)/epub/$(OUTPUT_FILENAME).epub: $(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES) \
-                                       $(COVER_IMAGE)
-  mkdir -p $(BUILD)/epub
-  pandoc $(ARGS) --epub-cover-image=$(COVER_IMAGE) -o $@ $(CHAPTERS)
+$(BUILD)/epub/$(OUTPUT_FILENAME).epub:	$(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES) \
+					$(COVER_IMAGE)
+	mkdir -p $(BUILD)/epub
+	pandoc $(ARGS) --epub-cover-image=$(COVER_IMAGE) -o $@ $(CHAPTERS)
 
-$(BUILD)/html/$(OUTPUT_FILENAME).html: $(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES)
-  mkdir -p $(BUILD)/html
-  pandoc $(ARGS) --standalone --to=html5 -o $@ $(CHAPTERS)
-  cp -R $(IMAGES_FOLDER)/ $(BUILD)/html/$(IMAGES_FOLDER)/
-  cp $(CSS_FILE) $(BUILD)/html/$(CSS_FILE)
+$(BUILD)/html/$(OUTPUT_FILENAME).html:	$(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES)
+	mkdir -p $(BUILD)/html
+	pandoc $(ARGS) --standalone --to=html5 -o $@ $(CHAPTERS)
+	cp -R $(IMAGES_FOLDER)/ $(BUILD)/html/$(IMAGES_FOLDER)/
+	cp $(CSS_FILE) $(BUILD)/html/$(CSS_FILE)
 
-$(BUILD)/pdf/$(OUTPUT_FILENAME).pdf: $(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES)
-  mkdir -p $(BUILD)/pdf
-  pandoc $(ARGS) -V documentclass=$(LATEX_CLASS) -o $@ $(CHAPTERS)
+$(BUILD)/pdf/$(OUTPUT_FILENAME).pdf:	$(MAKEFILE) $(METADATA) $(CHAPTERS) $(CSS_FILE) $(IMAGES)
+	mkdir -p $(BUILD)/pdf
+	pandoc $(ARGS) -V documentclass=$(LATEX_CLASS) -o $@ $(CHAPTERS)