diff --git a/src/vs/editor/common/model/tokensStore.ts b/src/vs/editor/common/model/tokensStore.ts
index 359c755e057..d77bb8b7de6 100644
--- a/src/vs/editor/common/model/tokensStore.ts
+++ b/src/vs/editor/common/model/tokensStore.ts
@@ -804,7 +804,7 @@ export class TokensStore2 {
 				aIndex++;
 			}
 
-			const aMetadata = aTokens.getMetadata(aIndex - 1 > 0 ? aIndex - 1 : aIndex);
+			const aMetadata = aTokens.getMetadata(Math.min(Math.max(0, aIndex - 1), aLen - 1));
 			const languageId = TokenMetadata.getLanguageId(aMetadata);
 			const tokenType = TokenMetadata.getTokenType(aMetadata);