diff --git a/Makefile b/Makefile
index f79a903b..73169155 100644
--- a/Makefile
+++ b/Makefile
@@ -10,16 +10,16 @@ noexternallink:
 
 nolicenselanguage:
 	@echo -e "\nLines with only 1 or no language/license entry:"
-	@sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '^ *\* ' | egrep -v '` `'
+	@! sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '^ *\* ' | egrep -v '` `'
 
 nofullstop:
 	@echo -e "\nLines without a full stop after description:"
-	-@sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '[a-z] \(\['
-	-@sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '[a-z] `'
+	@! sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '[a-z] \(\['
+	@! sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep '[a-z] `'
 
 longdescriptions:
 	@echo -e "\nDescriptions exceeding 250 chars:"
-	@sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep --only-matching '\) - [Aa-Zz|.|\(|\)|/| |,|-]*\s\(\[' README.md | grep  '.\{257\}'
+	@! sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep --only-matching '\) - [Aa-Zz|.|\(|\)|/| |,|-]*\s\(\[' README.md | grep  '.\{257\}'
 
 listlicenses:
 	@echo -e "\nList of licenses:"
@@ -27,7 +27,7 @@ listlicenses:
 
 syntaxerrors:
 	@echo -e "\n Syntax errors:" 
-	@sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep  '\)\(|``'
+	@! sed -n -e '/BEGIN SOFTWARE LIST/,/END SOFTWARE LIST/ p' README.md | egrep  '\)\(|``'
 
 contrib:
 	@git shortlog -sne