diff --git a/Syntaxes/Sass.sublime-syntax b/Syntaxes/Sass.sublime-syntax
index 74645952..5d104823 100644
--- a/Syntaxes/Sass.sublime-syntax
+++ b/Syntaxes/Sass.sublime-syntax
@@ -380,7 +380,7 @@ contexts:
         - meta_scope: meta.selector.css
         - include: selector-parts
     # custom elements
-    - match: '\s*({{custom_elements}})(?![-:])'
+    - match: '\s*({{custom_elements}})(?!-|\s*:)'
       captures:
         1: entity.name.tag.custom.css
       push:
diff --git a/Tests/syntax_test_sass.sass b/Tests/syntax_test_sass.sass
index bde37022..ad513859 100644
--- a/Tests/syntax_test_sass.sass
+++ b/Tests/syntax_test_sass.sass
@@ -101,6 +101,8 @@ input:not([type="radio"]):not(h1):not(custom-element):not(%placeholder), select,
 //                                             ^ support.constant.property-value.css
 //                                                    ^ support.constant.property-value.css
 //                                                          ^ support.constant.property-value.css
+  align-self : baseline
+// ^ support.type.property-name.css
   object-fit: scale-down
 // ^^^^^^^^^ support.type.property-name.css
 // ^ - meta.selector
diff --git a/Tests/syntax_test_scss.scss b/Tests/syntax_test_scss.scss
index fdae0d91..d4afbbdf 100644
--- a/Tests/syntax_test_scss.scss
+++ b/Tests/syntax_test_scss.scss
@@ -113,6 +113,8 @@ selector-ish::before[data-type="text"]:not(:first-child),
 //                        ^ punctuation.section.property-list.begin
   color: #00ff00;
   height: 97%;
+  align-self : baseline;
+// ^ support.type.property-name.css
   object-fit: scale-down;
 // ^ support.type.property-name.css
 // ^ - meta.selector