diff --git a/public/app/plugins/datasource/loki/syntax.test.ts b/public/app/plugins/datasource/loki/syntax.test.ts
index 3b96c52841e..b2d88150907 100644
--- a/public/app/plugins/datasource/loki/syntax.test.ts
+++ b/public/app/plugins/datasource/loki/syntax.test.ts
@@ -21,6 +21,9 @@ describe('Loki syntax', () => {
     expect(Prism.highlight('{key="value"', syntax, 'loki')).toBe(
       '<span class="token context-labels"><span class="token punctuation">{</span><span class="token label-key attr-name">key</span>=<span class="token label-value attr-value">"value"</span></span>'
     );
+    expect(Prism.highlight('{Key="value"', syntax, 'loki')).toBe(
+      '<span class="token context-labels"><span class="token punctuation">{</span><span class="token label-key attr-name">Key</span>=<span class="token label-value attr-value">"value"</span></span>'
+    );
   });
   it('should highlight functions in Loki query correctly', () => {
     expect(Prism.highlight('rate({key="value"}[5m])', syntax, 'loki')).toContain(
diff --git a/public/app/plugins/datasource/loki/syntax.ts b/public/app/plugins/datasource/loki/syntax.ts
index cac467b365e..abb521b02e5 100644
--- a/public/app/plugins/datasource/loki/syntax.ts
+++ b/public/app/plugins/datasource/loki/syntax.ts
@@ -192,7 +192,7 @@ export const lokiGrammar: Grammar = {
         pattern: /#.*/,
       },
       'label-key': {
-        pattern: /[a-z_]\w*(?=\s*(=|!=|=~|!~))/,
+        pattern: /[a-zA-Z_]\w*(?=\s*(=|!=|=~|!~))/,
         alias: 'attr-name',
         greedy: true,
       },