diff --git a/apps/oxlint/src-js/package/rule_tester.ts b/apps/oxlint/src-js/package/rule_tester.ts
index d01d1dd3396f9..53c5aef1d34db 100644
--- a/apps/oxlint/src-js/package/rule_tester.ts
+++ b/apps/oxlint/src-js/package/rule_tester.ts
@@ -111,10 +111,19 @@ function getItOnly(): ItFn {
 /**
  * Configuration for `RuleTester`.
  */
-export type Config = Record<string, unknown>;
+export interface Config {
+  /**
+   * ESLint compatibility mode.
+   * If `true`, column offsets in diagnostics are incremented by 1, to match ESLint's behavior.
+   */
+  eslintCompat?: boolean;
+  [key: string]: unknown;
+}
 
 // Default shared config
-const DEFAULT_SHARED_CONFIG: Config = {};
+const DEFAULT_SHARED_CONFIG: Config = {
+  eslintCompat: false,
+};
 
 // `RuleTester` uses this config as its default. Can be overwritten via `RuleTester.setDefaultConfig()`.
 let sharedConfig: Config = DEFAULT_SHARED_CONFIG;
@@ -134,6 +143,11 @@ interface TestCase {
   options?: Options;
   before?: (this: this) => void;
   after?: (this: this) => void;
+  /**
+   * `true` to enable ESLint compatibility mode.
+   * See `Config` type.
+   */
+  eslintCompat?: boolean;
 }
 
 /**
@@ -429,7 +443,7 @@ function assertInvalidTestCasePasses(test: InvalidTestCase, plugin: Plugin, conf
       } else {
         // `error` is an error object
         assertInvalidTestCaseMessageIsCorrect(diagnostic, error, messages);
-        assertInvalidTestCaseLocationIsCorrect(diagnostic, error);
+        assertInvalidTestCaseLocationIsCorrect(diagnostic, error, config);
 
         // TODO: Test suggestions
       }
@@ -521,9 +535,14 @@ function assertInvalidTestCaseMessageIsCorrect(
  * Assert that location reported by rule under test matches the expected location.
  * @param diagnostic - Diagnostic emitted by rule under test
  * @param error - Error object from test case
+ * @param config - Config for this test case
  * @throws {AssertionError} If diagnostic's location does not match expected location
  */
-function assertInvalidTestCaseLocationIsCorrect(diagnostic: Diagnostic, error: Error) {
+function assertInvalidTestCaseLocationIsCorrect(
+  diagnostic: Diagnostic,
+  error: Error,
+  config: Config,
+) {
   interface Location {
     line?: number;
     column?: number;
@@ -534,13 +553,15 @@ function assertInvalidTestCaseLocationIsCorrect(diagnostic: Diagnostic, error: E
   const actualLocation: Location = {};
   const expectedLocation: Location = {};
 
+  const columnOffset = config.eslintCompat === true ? 1 : 0;
+
   if (hasOwn(error, "line")) {
     actualLocation.line = diagnostic.line;
     expectedLocation.line = error.line;
   }
 
   if (hasOwn(error, "column")) {
-    actualLocation.column = diagnostic.column;
+    actualLocation.column = diagnostic.column + columnOffset;
     expectedLocation.column = error.column;
   }
 
@@ -550,7 +571,7 @@ function assertInvalidTestCaseLocationIsCorrect(diagnostic: Diagnostic, error: E
   }
 
   if (hasOwn(error, "endColumn")) {
-    actualLocation.endColumn = diagnostic.endColumn;
+    actualLocation.endColumn = diagnostic.endColumn + columnOffset;
     expectedLocation.endColumn = error.endColumn;
   }
 
@@ -654,7 +675,19 @@ function createConfigForRun(config: Config | null): Config {
  * @returns Merged config
  */
 function createConfigForTest(test: TestCase, config: Config): Config {
-  // TODO: Merge properties of `test` into `config`
+  let isCloned = false;
+  function clone(): void {
+    if (!isCloned) {
+      config = { ...config };
+      isCloned = true;
+    }
+  }
+
+  // TODO: Merge more properties of `test` into `config`
+  if (hasOwn(test, "eslintCompat")) {
+    clone();
+    config.eslintCompat = test.eslintCompat;
+  }
   return config;
 }
 
diff --git a/apps/oxlint/test/rule_tester.test.ts b/apps/oxlint/test/rule_tester.test.ts
index b353c12bf84bd..811587a0d459b 100644
--- a/apps/oxlint/test/rule_tester.test.ts
+++ b/apps/oxlint/test/rule_tester.test.ts
@@ -816,4 +816,101 @@ describe("RuleTester", () => {
       expect(test.after.mock.contexts[0]).toBe(test);
     }
   });
+
+  describe("ESLint compat mode", () => {
+    it("enabled globally", () => {
+      RuleTester.setDefaultConfig({ eslintCompat: true });
+
+      const tester = new RuleTester();
+      tester.run("no-foo", simpleRule, {
+        valid: [],
+        invalid: [
+          {
+            code: "foo;",
+            errors: [
+              {
+                message: "No foo!",
+                line: 1,
+                column: 1,
+                endLine: 1,
+                endColumn: 4,
+              },
+            ],
+          },
+        ],
+      });
+      expect(runCases()).toEqual([null]);
+    });
+
+    it("enabled in `RuleTester` options", () => {
+      const tester = new RuleTester({ eslintCompat: true });
+      tester.run("no-foo", simpleRule, {
+        valid: [],
+        invalid: [
+          {
+            code: "foo;",
+            errors: [
+              {
+                message: "No foo!",
+                line: 1,
+                column: 1,
+                endLine: 1,
+                endColumn: 4,
+              },
+            ],
+          },
+        ],
+      });
+      expect(runCases()).toEqual([null]);
+    });
+
+    it("enabled in in individual test cases", () => {
+      const tester = new RuleTester();
+      tester.run("no-foo", simpleRule, {
+        valid: [],
+        invalid: [
+          {
+            code: "foo = 1;",
+            // Default: eslintCompat: false
+            errors: [
+              {
+                message: "No foo!",
+                line: 1,
+                column: 0,
+                endLine: 1,
+                endColumn: 3,
+              },
+            ],
+          },
+          {
+            code: "foo = 1;",
+            eslintCompat: false,
+            errors: [
+              {
+                message: "No foo!",
+                line: 1,
+                column: 0,
+                endLine: 1,
+                endColumn: 3,
+              },
+            ],
+          },
+          {
+            code: "foo = 1;",
+            eslintCompat: true,
+            errors: [
+              {
+                message: "No foo!",
+                line: 1,
+                column: 1, // 1 not 0
+                endLine: 1,
+                endColumn: 4, // 4 not 3
+              },
+            ],
+          },
+        ],
+      });
+      expect(runCases()).toEqual([null, null, null]);
+    });
+  });
 });