diff --git a/packages/form-core/src/validate/ValidateMixin.js b/packages/form-core/src/validate/ValidateMixin.js
index ac40528c0..88fe89a1b 100644
--- a/packages/form-core/src/validate/ValidateMixin.js
+++ b/packages/form-core/src/validate/ValidateMixin.js
@@ -470,7 +470,7 @@ export const ValidateMixinImplementation = superclass =>
         if (!(v instanceof Validator)) {
           // throws in constructor are not visible to end user so we do both
           const errorType = Array.isArray(v) ? 'array' : typeof v;
-          const errorMessage = `Validators array only accepts class instances of Validator. Type "${errorType}" found.`;
+          const errorMessage = `Validators array only accepts class instances of Validator. Type "${errorType}" found. This may be caused by having multiple installations of @lion/form-core.`;
           // eslint-disable-next-line no-console
           console.error(errorMessage, this);
           throw new Error(errorMessage);
diff --git a/packages/form-core/test-suites/ValidateMixin.suite.js b/packages/form-core/test-suites/ValidateMixin.suite.js
index fb6d1b8a7..06acf1902 100644
--- a/packages/form-core/test-suites/ValidateMixin.suite.js
+++ b/packages/form-core/test-suites/ValidateMixin.suite.js
@@ -70,7 +70,7 @@ export function runValidateMixinSuite(customConfig) {
         const stub = sinon.stub(console, 'error');
         const el = /** @type {ValidateElement} */ (await fixture(html`<${tag}></${tag}>`));
         const errorMessage =
-          'Validators array only accepts class instances of Validator. Type "array" found.';
+          'Validators array only accepts class instances of Validator. Type "array" found. This may be caused by having multiple installations of @lion/form-core.';
         expect(() => {
           // @ts-expect-error putting the wrong value on purpose
           el.validators = [[new Required()]];
@@ -78,7 +78,7 @@ export function runValidateMixinSuite(customConfig) {
         expect(stub.args[0][0]).to.equal(errorMessage);
 
         const errorMessage2 =
-          'Validators array only accepts class instances of Validator. Type "string" found.';
+          'Validators array only accepts class instances of Validator. Type "string" found. This may be caused by having multiple installations of @lion/form-core.';
         expect(() => {
           // @ts-expect-error because we purposely put a wrong type
           el.validators = ['required'];