diff --git a/.gitignore b/.gitignore
index 12dd925..e3c9d29 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 # Editor files
 *.sublime-workspace
+*.sublime-project
 
 # Other
 .idea
diff --git a/PowerShell.sublime-project b/PowerShell.sublime-project
deleted file mode 100644
index 9d0052b..0000000
--- a/PowerShell.sublime-project
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-	"folders":
-	[
-		{
-			"follow_symlinks": true,
-			"path": ".",
-		},
-	],
-}
diff --git a/PowerShell.sublime-syntax b/PowerShell.sublime-syntax
index 8979372..b568e5d 100644
--- a/PowerShell.sublime-syntax
+++ b/PowerShell.sublime-syntax
@@ -837,6 +837,8 @@ contexts:
     - match: \]
       scope: punctuation.section.brackets.end.powershell
       pop: 1
+    - match: \b(?:in|out|ref)\b
+      scope: storage.modifier.powershell
     - match: \p{L}[\p{L}\p{N}]+(\.)
       scope: meta.generic-name.powershell
       captures:
diff --git a/tests/syntax_test_PowerShell.ps1 b/tests/syntax_test_PowerShell.ps1
index 5929af5..96a4e10 100644
--- a/tests/syntax_test_PowerShell.ps1
+++ b/tests/syntax_test_PowerShell.ps1
@@ -2451,3 +2451,20 @@ function Process-DeploymentConfig {
   Resolve-ConfigPath -Path "Foo" -PathVariables $PathVariables
 # @@@@@@@@@@@@@@@@@@ reference
 }
+
+    # https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_ref?view=powershell-7.6
+    # Create a value type variable.
+    $i = 0
+    # Create a reference type variable.
+    $iRef = [ref]0
+#            ^^^ storage.modifier.powershell
+    # Invoke a scriptblock to attempt to change both values.
+    &{$i++;$iRef.Value++}
+    # Output the results.
+    "`$i = $i;`$iRef = $($iRef.Value)"
+
+    [int]::TryParse("15", ([ref]$number))
+#    ^^^ storage.type.powershell
+#        ^^ punctuation.accessor.double-colon.powershell
+#          @@@@@@@@ reference
+#                           ^^^ storage.modifier.powershell