diff --git a/pdf/en-us/Makefile b/pdf/en-us/Makefile
index 7846a52..51bf612 100644
--- a/pdf/en-us/Makefile
+++ b/pdf/en-us/Makefile
@@ -6,8 +6,8 @@ revision = $(shell git describe --always --tags)
 all: revision pdf
 
 revision:
-	@echo '% Autogenerated, do not edit' > revision.tex
-	@echo '\\newcommand{\\revision}{'$(revision)'}' >> revision.tex
+	printf '%% Autogenerated, do not edit\n' > revision.tex
+	printf '\\newcommand{\\revision}{'$(revision)'}' >> revision.tex
 
 pdf: markdown
 	@echo "Compiling PDF file..."
diff --git a/pdf/zh-cn/Makefile b/pdf/zh-cn/Makefile
index ac0b42a..6a6f940 100644
--- a/pdf/zh-cn/Makefile
+++ b/pdf/zh-cn/Makefile
@@ -6,8 +6,8 @@ revision = $(shell git describe --always --tags)
 all: revision pdf
 
 revision:
-	@echo '% Autogenerated, do not edit' > revision.tex
-	@echo '\\newcommand{\\revision}{'$(revision)'}' >> revision.tex
+	printf '%% Autogenerated, do not edit\n' > revision.tex
+	printf '\\newcommand{\\revision}{'$(revision)'}' >> revision.tex
 
 pdf: markdown
 	@echo "Compiling PDF file..."