diff --git a/src/resolve/forceIgnore.ts b/src/resolve/forceIgnore.ts
index 299fc69470..40f6c601d2 100644
--- a/src/resolve/forceIgnore.ts
+++ b/src/resolve/forceIgnore.ts
@@ -21,22 +21,19 @@ export class ForceIgnore {
 
   public constructor(forceIgnorePath = '') {
     try {
-      let contents = readFileSync(forceIgnorePath, 'utf-8');
+      const contents = readFileSync(forceIgnorePath, 'utf-8');
       // check if file `.forceignore` exists
       if (contents !== undefined) {
         // check for windows style separators (\) and warn
         if (contents.includes('\\')) {
-          const lifecycle = Lifecycle.getInstance();
-          // cannot await a method in a constructor
-          void lifecycle.emitWarning(
-            'Your .forceignore file incorrectly uses the backslash ("\\") as a folder separator; it should use the slash ("/") instead. We currently accept both separators, but we plan to stop supporting the backslash soon.'
+          // void because you cannot await a method in a constructor
+          void Lifecycle.getInstance().emitWarning(
+            'Your .forceignore file incorrectly uses the backslash ("\\") as a folder separator; it should use the slash ("/") instead. The ignore rules will not work as expected until you fix this.'
           );
-          // TODO: change this in v56 to only emit warning but NOT fix file
-          contents = contents.replace(/\\/g, '/');
         }
-
         // add the default ignore paths, and then parse the .forceignore file
-        this.parser = ignore().add(`${contents}\n${this.DEFAULT_IGNORE.join('\n')}`);
+        this.parser = ignore().add(`${this.DEFAULT_IGNORE.join('\n')}\n${contents}`);
+
         this.forceIgnoreDirectory = dirname(forceIgnorePath);
       }
     } catch (e) {
diff --git a/test/resolve/forceIgnore.test.ts b/test/resolve/forceIgnore.test.ts
index 3a58cd8064..47df03ffa6 100644
--- a/test/resolve/forceIgnore.test.ts
+++ b/test/resolve/forceIgnore.test.ts
@@ -9,7 +9,7 @@ import { expect } from 'chai';
 import { createSandbox } from 'sinon';
 import * as fs from 'graceful-fs';
 import { Lifecycle } from '@salesforce/core';
-import { ForceIgnore } from '../../src';
+import { ForceIgnore } from '../../src/resolve/forceIgnore';
 import * as fsUtil from '../../src/utils/fileSystemHandler';
 
 const env = createSandbox();
@@ -29,14 +29,13 @@ describe('ForceIgnore', () => {
   });
 
   it('Should ignore files with a given pattern', () => {
-    const readStub = env.stub(fs, 'readFileSync');
-    readStub.withArgs(forceIgnorePath).returns(testPattern);
+    env.stub(fs, 'readFileSync').returns(testPattern);
     const forceIgnore = new ForceIgnore(forceIgnorePath);
     expect(forceIgnore.accepts(testPath)).to.be.false;
     expect(forceIgnore.denies(testPath)).to.be.true;
   });
 
-  it('Should ignore files with windows separators', () => {
+  it('windows separators no longer have any effect', () => {
     const lifecycleStub = env.stub(Lifecycle.prototype, 'emitWarning');
     const forceIgnoreEntry = 'force-app\\main\\default\\classes\\myApex.*';
     const pathToClass = join('force-app', 'main', 'default', 'classes', 'myApex.cls');
@@ -44,7 +43,7 @@ describe('ForceIgnore', () => {
 
     const forceIgnore = new ForceIgnore();
 
-    expect(forceIgnore.accepts(pathToClass)).to.be.false;
+    expect(forceIgnore.accepts(pathToClass)).to.be.true;
     expect(lifecycleStub.callCount).to.equal(1);
   });
 
@@ -110,5 +109,16 @@ describe('ForceIgnore', () => {
       expect(forceIgnore.accepts(manifestPath)).to.be.false;
       expect(forceIgnore.denies(manifestPath)).to.be.true;
     });
+
+    it('Should allow .forceignore file to override defaults', () => {
+      // tamper with the file
+      env.restore();
+      env.stub(fs, 'readFileSync').returns('!**/.*');
+      forceIgnore = new ForceIgnore();
+
+      const dotFilePath = join(root, '.foo');
+      expect(forceIgnore.accepts(dotFilePath)).to.be.true;
+      expect(forceIgnore.denies(dotFilePath)).to.be.false;
+    });
   });
 });