diff --git a/Linker_QuickAction.sh b/Linker_workflow.sh
similarity index 96%
rename from Linker_QuickAction.sh
rename to Linker_workflow.sh
index 8f4012b..91286ad 100755
--- a/Linker_QuickAction.sh
+++ b/Linker_workflow.sh
@@ -1,7 +1,7 @@
 #!/bin/zsh
 # shellcheck shell=bash
 
-# Linker Finder QuickAction (workflow)
+# Linker Finder workflow (QuickAction or Service)
 # version 1.0.1
 
 export LANG=en_US.UTF-8
diff --git a/README b/README
index 058ec4d..be96865 100644
--- a/README
+++ b/README
@@ -1,8 +1,7 @@
 Linker is a macOS shell script and Finder QuickAction to create relative or absolute symbolic links, hard links, Finder aliases, Bookmark files, file clones or legacy file copies
 
 Latest release: https://github.com/JayBrown/Linker/releases/latest
-Successfully tested on: macOS 10.15.7 (Catalina)
-Not working on: OS X 10.9.5 (Mavericks)
+Successfully tested on: macOS 10.15.7 (Catalina) & macOS 10.13.6 (High Sierra)
 
 * install linker shell script into your $PATH
 
@@ -19,7 +18,9 @@ Not working on: OS X 10.9.5 (Mavericks)
 * execute the following, if the script doesn't run: chmod +x ./linker
 
 * Mojave & later: install QuickAction workflow with Automator Installer
-* on older systems the QuickAction format is either not supported or might not work properly as a Service workflow, and you need to create your own Service workflow in Automator
+* High Sierra & earlier: install the Service workflow with Automator Installer
+
+* Mojave 10.14.3 and earlier (optional): install the Swift 5 Runtime Support for Command Line Tools: https://support.apple.com/kb/DL1998?locale=en_US
 
 In Finder you can just use the QuickAction from the contextual menu (or the Service on older systems).
 
diff --git a/linker b/linker
index eeaf121..ce68e30 100755
--- a/linker
+++ b/linker
@@ -1,7 +1,7 @@
 #!/bin/zsh
 # shellcheck shell=bash
 
-# Linker v0.4
+# Linker v0.4.1
 
 export LANG=en_US.UTF-8
 export SYSTEM_VERSION_COMPAT=0
@@ -11,21 +11,41 @@ uiprocess="Linker"
 procid="local.lcars.Linker"
 
 # check system version
+swiftlib="/usr/lib/swift/libswiftCore.dylib"
 sysvers=$(sw_vers -productVersion)
 doublealias=false
+noalisma=false
 noapfs=false
 vmaj=$(echo "$sysvers" | awk -F"." '{print $1}')
 if [[ $vmaj -lt 11 ]] ; then
 	vmin=$(echo "$sysvers" | awk -F"." '{print $2}')
-	if [[ $vmin -lt 13 ]] ; then # no APFS support
-		noapfs=true
-		if [[ $vmin -eq 12 ]] ; then
-			vfix=$(echo "$sysvers" | awk -F"." '{print $3}')
-			if [[ $vfix -lt 6 ]] ; then # potentially buggy support for new Alias format: needs to be separated from Bookmark file
-				doublealias=true
+	vfix=$(echo "$sysvers" | awk -F"." '{print $3}')
+	if [[ $vmin -eq 14 ]] ; then
+		if [[ $vfix -le 3 ]] ; then # Mojave 10.14.3 and earlier: needs Swift libraries for alisma
+			if ! [[ -f "$swiftlib" ]] ; then
+				noalisma=true
 			fi
-		elif [[ $vmin -lt 12 ]] ; then # old Alias format: needs to be separated from Bookmark file
-			doublealias=true
+		fi
+	elif [[ $vmin -eq 13 ]] ; then # High Sierra: needs Swift libraries for alisma
+		if ! [[ -f "$swiftlib" ]] ; then
+			noalisma=true
+		fi
+	elif [[ $vmin -le 12 ]] ; then # Sierra and earlier
+		noapfs=true # no APFS support on Sierra and earlier
+		if [[ $vmin -ge 11 ]] ; then  # Swift libraries needed for: El Capitan & Sierra
+			if ! [[ -f "$swiftlib" ]] ; then
+				noalisma=true
+			else # Swift libraries are present
+				if [[ $vmin -eq 12 ]] ; then
+					if [[ $vfix -lt 6 ]] ; then # potentially buggy support for new Alias format: needs to be separated from Bookmark file
+						doublealias=true
+					fi
+				elif [[ $vmin -eq 11 ]] ; then # old Alias format: needs to be separated from Bookmark file			
+					doublealias=true
+				fi
+			fi
+		else # Yosemite and earlier: no Swift library & alisma support
+			noalisma=true
 		fi
 	fi
 fi
@@ -184,10 +204,14 @@ elif [[ $1 == "-s" ]] ; then
 	cli=true
 	shift
 elif [[ $1 == "-b" ]] ; then
-	if $doublealias ; then
-		bookmark=true
-	else
+	if $noalisma ; then
 		finderalias=true
+	else
+		if $doublealias ; then
+			bookmark=true
+		else
+			finderalias=true
+		fi
 	fi
 	cli=true
 	shift
@@ -3486,26 +3510,32 @@ fi
 
 # export additional path & check for availability of alisma
 export PATH=$PATH:"$bindir"
-xalisma=true
-if ! command -v alisma &>/dev/null ; then
-	chmod +x "$bindir/alisma" 2>/dev/null
+if $noalisma ; then
+	xalisma=false
+else
+	xalisma=true
 	if ! command -v alisma &>/dev/null ; then
-		xalisma=false
+		chmod +x "$bindir/alisma" 2>/dev/null
+		if ! command -v alisma &>/dev/null ; then
+			xalisma=false
+		else
+			if ! alisma -h | head -1 | grep "^alisma v[1-9] usage:$" &>/dev/null ; then
+				xalisma=false
+			fi
+		fi
 	else
 		if ! alisma -h | head -1 | grep "^alisma v[1-9] usage:$" &>/dev/null ; then
 			xalisma=false
 		fi
 	fi
-else
-	if ! alisma -h | head -1 | grep "^alisma v[1-9] usage:$" &>/dev/null ; then
-		xalisma=false
-	fi
 fi
 if $cli ; then # standard alias files can always be created via Finder
-	if $bookmark && ! $xalisma ; then
-		_sysbeep &
-		_notify "⚠️ Bookmark files unsupported!" "alisma CLI is missing!"
-		exit
+	if $bookmark ; then
+		if $noalisma || ! $xalisma ; then
+			_sysbeep &
+			_notify "⚠️ Bookmark files unsupported!" "alisma CLI is missing!"
+			exit
+		fi
 	fi
 fi