diff --git a/pymolfile/molfile/molfile_plugins/compile/silence_plugins.sh b/pymolfile/molfile/molfile_plugins/compile/silence_plugins.sh
index c5e2590b54671a06bb15af0bf582b64f1611bbac..8cd86c2f2f094bc199966e355a6bbe7ec2a0b760 100755
--- a/pymolfile/molfile/molfile_plugins/compile/silence_plugins.sh
+++ b/pymolfile/molfile/molfile_plugins/compile/silence_plugins.sh
@@ -38,9 +38,9 @@ do
 	#firstline=`cat $file | head -n 1`
 	#sed -i.bak '1a\'$'\n'${firstline}$'\n' $file
 	sed -i.bak '1i\'$'\n''#endif'$'\n' $file
-	sed -i.bak '1i\'$'\n''char msgstr'${fcount}'[512], msgout'${fcount}'[512], msgerr'${fcount}'[512];'$'\n' $file
-	sed -i.bak '1i\'$'\n''#define SILENCE_'${fcount}'_PLUGIN 1'$'\n' $file 
-	sed -i.bak '1i\'$'\n''#ifndef SILENCE_'${fcount}'_PLUGIN'$'\n' $file 
+	sed -i "" '1i\'$'\n''char msgstr'${fcount}'[512], msgout'${fcount}'[512], msgerr'${fcount}'[512];'$'\n' $file
+	sed -i "" '1i\'$'\n''#define SILENCE_'${fcount}'_PLUGIN 1'$'\n' $file 
+	sed -i "" '1i\'$'\n''#ifndef SILENCE_'${fcount}'_PLUGIN'$'\n' $file 
 	#sed -i.bak $incline'a\'$'\n''#define SILENCE_PLUGINS_'${fcount}' 1'$'\n' $file 
 	#sed -i.bak $incline'a\'$'\n''#ifndef SILENCE_PLUGINS_'${fcount}''$'\n' $file 
 	singlelines1=`cat $file | grep -n -e "$pattern1" | grep -v "^--" | awk -F":" '{print $1}'`