diff --git a/fragments/arguments.sh b/fragments/arguments.sh
index d682862..6c01519 100644
--- a/fragments/arguments.sh
+++ b/fragments/arguments.sh
@@ -1,7 +1,8 @@
 # MARK: check minimal macOS requirement
 autoload is-at-least
 
-if ! is-at-least 10.14 $(sw_vers -productVersion); then
+installedOSversion=$(sw_vers -productVersion)
+if ! is-at-least 10.14 $installedOSversion; then
     printlog "Installomator requires at least macOS 10.14 Mojave."
     exit 98
 fi
diff --git a/fragments/functions.sh b/fragments/functions.sh
index f5d5137..b1ba7a0 100644
--- a/fragments/functions.sh
+++ b/fragments/functions.sh
@@ -345,8 +345,17 @@ installAppWithPath() { # $1: path to app to install in $targetDir
         cleanupAndExit 5 "Team IDs do not match"
     fi
 
-    # versioncheck
-    # credit: Søren Theilgaard (@theilgaard)
+    # macOS versioncheck
+    minimumOSversion=$(defaults read $appPath/Contents/Info.plist LSMinimumSystemVersion)
+    if [[ $minimumOSversion =~ '[0-9.]*' ]]; then
+        printlog "App has LSMinimumSystemVersion: $minimumOSversion"
+        if ! is-at-least $minimumOSversion $installedOSversion; then
+            printlog "App requires higher System Version than installed: $installedOSversion"
+            cleanupAndExit 6 "Installed macOS is too old for this app."
+        fi
+    fi
+
+    # app versioncheck
     appNewVersion=$(defaults read $appPath/Contents/Info.plist $versionKey)
     if [[ -n $appNewVersion && $appversion == $appNewVersion ]]; then
         printlog "Downloaded version of $name is $appNewVersion, same as installed."