diff --git a/core/models/config.js b/core/models/config.js
index 3347b44..8120fd8 100644
--- a/core/models/config.js
+++ b/core/models/config.js
@@ -340,7 +340,7 @@ class Config {
       ...opts,
     };
 
-    const { error } = optionsSchema.validate(opts);
+    const { error, value } = optionsSchema.validate(opts, { stripUnknown: true });
     if (error) {
       const details = (error?.details || [])
         .flatMap((detail) => [detail.message, detail.context.message])
@@ -349,7 +349,7 @@ class Config {
       throw new Error(`Config schema validation failed: ${details}`);
     }
 
-    return new Config(opts);
+    return new Config(value);
   }
 
   /**
@@ -384,7 +384,7 @@ class Config {
       ...data,
     };
 
-    const { error } = optionsSchema.validate(opts);
+    const { error, value } = optionsSchema.validate(opts, { stripUnknown: true });
     if (error) {
       const details = (error?.details || [])
         .flatMap((detail) => [detail.message, detail.context.message])
@@ -393,7 +393,7 @@ class Config {
       throw new Error(`Config file ${configFilePath} contains errors :\n${details}`);
     }
 
-    return new Config(opts);
+    return new Config(value);
   }
 
   /**
diff --git a/core/models/config.spec.js b/core/models/config.spec.js
index eb89ad4..44d1dcd 100644
--- a/core/models/config.spec.js
+++ b/core/models/config.spec.js
@@ -216,4 +216,19 @@ css_custom: styles.css
     const config = Config.get('../config.yml');
     expect(config.canCssCustom()).toBe(true);
   });
+
+  it('should ignore unknown options', () => {
+    const configContent = `
+${minimalConfigContent}
+unknown: true
+        `;
+
+    mockReadConfigFile.mockImplementationOnce(() => configContent);
+    const config = Config.get('../config.yml');
+    expect(config.opts).not.toEqual(
+      expect.objectContaining({
+        unknown: true,
+      }),
+    );
+  });
 });