diff --git a/upgrade-v1.0x-v1.3x.sh b/upgrade-v1.0x-v1.3x.sh
index 1b5fb4a..89d0b9d 100755
--- a/upgrade-v1.0x-v1.3x.sh
+++ b/upgrade-v1.0x-v1.3x.sh
@@ -7,7 +7,7 @@ CONTACT="http://www.netpower.fr/osync - ozy@netpower.fr"
 OLD_PROGRAM_VERSION="v1.0x-v1.2x"
 NEW_PROGRAM_VERSION="v1.3x"
 CONFIG_FILE_REVISION=1.3.0
-PROGRAM_BUILD=2016121101
+PROGRAM_BUILD=2019051801
 
 ## type -p does not work on platforms other than linux (bash). If if does not work, always assume output is not a zero exitcode
 if ! type "$BASH" > /dev/null; then
@@ -515,15 +515,15 @@ function AddMissingConfigOptionsAndFixBooleans {
 			echo "Added missing ${KEYWORDS[$counter]} config option with default option [${VALUES[$counter]}]"
 		else
 			# Not the most elegant but the quickest way :)
-			if [ "${VALUES[$counter]}" == true ]; then
+			if grep "^{$KEYWORDS[$counter]}=yes" > /dev/null "$config_file"; then
 				sed -i'.tmp' 's/^'${KEYWORDS[$counter]}'=.*/'${KEYWORDS[$counter]}'=true/g' "$config_file"
 				if [ $? -ne 0 ]; then
 					echo "Cannot rewrite ${[KEYWORDS[$counter]} boolean to true."
 					exit 1
 				fi
-			elif [ "${VALUES[$counter]}" == false ]; then
+			elif grep "^{$KEYWORDS[$counter]}=no" > /dev/null "$config_file"; then
 				if [ $? -ne 0 ]; then
-					echo "Cannot ${[KEYWORDS[$counter]} boolean to false."
+					echo "Cannot rewrite ${[KEYWORDS[$counter]} boolean to false."
 					exit 1
 				fi
 				sed -i'.tmp' 's/^'${KEYWORDS[$counter]}'=.*/'${KEYWORDS[$counter]}'=false/g' "$config_file"
@@ -550,10 +550,12 @@ function RewriteSections {
 function UpdateConfigHeader {
 	local config_file="${1}"
 
-	# "onfig file rev" to deal with earlier variants of the file where c was lower or uppercase
-	sed -i'.tmp' 's/.*onfig file rev.*//' "$config_file"
-	sed -i'.tmp' '/^\[GENERAL\]$/a\'$'\n'CONFIG_FILE_REVISION=$CONFIG_FILE_REVISION$'\n''' "$config_file"
-	rm -f "$config_file.tmp"
+	if ! grep "^CONFIG_FILE_REVISION=" > /dev/null "$config_file"; then
+		# "onfig file rev" to deal with earlier variants of the file where c was lower or uppercase
+		sed -i'.tmp' 's/.*onfig file rev.*//' "$config_file"
+		sed -i'.tmp' '/^\[GENERAL\]$/a\'$'\n'CONFIG_FILE_REVISION=$CONFIG_FILE_REVISION$'\n''' "$config_file"
+		rm -f "$config_file.tmp"
+	fi
 }
 
 _QUICK_SYNC=0