diff --git a/devtools/client/debugger/src/components/Editor/InlinePreviews.js b/devtools/client/debugger/src/components/Editor/InlinePreviews.js
index b3df0e82a507..25d50d2d9f03 100644
--- a/devtools/client/debugger/src/components/Editor/InlinePreviews.js
+++ b/devtools/client/debugger/src/components/Editor/InlinePreviews.js
@@ -54,6 +54,7 @@ class InlinePreviews extends Component<Props> {
           return (
             <InlinePreviewRow
               editor={editor}
+              key={line}
               line={lineNum}
               previews={previews[line]}
               numColumnBreakpoints={numColumnBreakpoints}