diff --git a/src/vs/editor/common/model.ts b/src/vs/editor/common/model.ts
index e26df375fa9..8c7edd2e6f8 100644
--- a/src/vs/editor/common/model.ts
+++ b/src/vs/editor/common/model.ts
@@ -386,7 +386,7 @@ export class TextModelResolvedOptions {
 		defaultEOL: DefaultEndOfLine;
 		trimAutoWhitespace: boolean;
 	}) {
-		this.tabSize = src.tabSize | 0;
+		this.tabSize = Math.max(1, src.tabSize | 0);
 		this.indentSize = src.tabSize | 0;
 		this.insertSpaces = Boolean(src.insertSpaces);
 		this.defaultEOL = src.defaultEOL | 0;