diff --git a/joi/joi-tests.ts b/joi/joi-tests.ts
index c832b3eb05..7002a3872c 100644
--- a/joi/joi-tests.ts
+++ b/joi/joi-tests.ts
@@ -759,30 +759,57 @@ schema = Joi.lazy(() => schema)
 
 // --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
 
-Joi.validate(value, obj);
-Joi.validate(value, schema);
-Joi.validate(value, schema, validOpts);
-Joi.validate(value, schema, validOpts, (err, value) => {
-	x = value;
-	str = err.message;
-	str = err.details[0].path;
-	str = err.details[0].message;
-	str = err.details[0].type;
-});
-Joi.validate(value, schema, (err, value) => {
-	x = value;
-	str = err.message;
-	str = err.details[0].path;
-	str = err.details[0].message;
-	str = err.details[0].type;
-});
-// variant
-Joi.validate(num, schema, validOpts, (err, value) => {
-	num = value;
-});
+namespace validate_tests {
+    {
+        Joi.validate(value, obj);
+        Joi.validate(value, schema);
+        Joi.validate(value, schema, validOpts);
+        Joi.validate(value, schema, validOpts, (err, value) => {
+            x = value;
+            str = err.message;
+            str = err.details[0].path;
+            str = err.details[0].message;
+            str = err.details[0].type;
+        });
+        Joi.validate(value, schema, (err, value) => {
+            x = value;
+            str = err.message;
+            str = err.details[0].path;
+            str = err.details[0].message;
+            str = err.details[0].type;
+        });
+        // variant
+        Joi.validate(num, schema, validOpts, (err, value) => {
+            num = value;
+        });
+
+        // plain opts
+        Joi.validate(value, {});
+    }
+
+    {
+        let value = { username: 'example', password: 'example' };
+        let schema = Joi.object().keys({
+            username: Joi.string().max(255).required(),
+            password: Joi.string().regex(/^[a-zA-Z0-9]{3,255}$/).required(),
+        });
+        let returnValue: Joi.ValidationResult<typeof value>;
+
+        returnValue = Joi.validate(value);
+        value = Joi.validate(value, (err, value) => value);
+
+        returnValue = Joi.validate(value, schema);
+        returnValue = Joi.validate(value, obj);
+        value = Joi.validate(value, obj, (err, value) => value);
+        value = Joi.validate(value, schema, (err, value) => value);
+
+        returnValue = Joi.validate(value, schema, validOpts);
+        returnValue = Joi.validate(value, obj, validOpts);
+        value = Joi.validate(value, obj, validOpts, (err, value) => value);
+        value = Joi.validate(value, schema, validOpts, (err, value) => value);
+    }
+}
 
-// plain opts
-Joi.validate(value, {});
 
 // --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ---
 
@@ -856,4 +883,4 @@ schema = Joi.raw();
 schema = Joi.raw(bool);
 schema = Joi.empty();
 schema = Joi.empty(str);
-schema = Joi.empty(anySchema);
\ No newline at end of file
+schema = Joi.empty(anySchema);
diff --git a/joi/joi.d.ts b/joi/joi.d.ts
index a4a029f737..9a7d73cbbf 100644
--- a/joi/joi.d.ts
+++ b/joi/joi.d.ts
@@ -842,9 +842,18 @@ declare module 'joi' {
 	/**
 	 * Validates a value using the given schema and options.
 	 */
-	export function validate<T>(value: T, schema: Schema, callback: (err: ValidationError, value: T) => void): void;
-	export function validate<T>(value: T, schema: Object, callback: (err: ValidationError, value: T) => void): void;
-	export function validate<T>(value: T, schema: Object, options?: ValidationOptions, callback?: (err: ValidationError, value: T) => void): ValidationResult<T>;
+	export function validate<T>(value: T): ValidationResult<T>;
+	export function validate<T, R>(value: T, callback: (err: ValidationError, value: T) => R): R;
+
+	export function validate<T>(value: T, schema: Schema): ValidationResult<T>;
+	export function validate<T>(value: T, schema: Object): ValidationResult<T>;
+	export function validate<T, R>(value: T, schema: Schema, callback: (err: ValidationError, value: T) => R): R;
+	export function validate<T, R>(value: T, schema: Object, callback: (err: ValidationError, value: T) => R): R;
+
+	export function validate<T>(value: T, schema: Schema, options: ValidationOptions): ValidationResult<T>;
+	export function validate<T>(value: T, schema: Object, options: ValidationOptions): ValidationResult<T>;
+	export function validate<T, R>(value: T, schema: Schema, options: ValidationOptions, callback: (err: ValidationError, value: T) => R): R;
+	export function validate<T, R>(value: T, schema: Object, options: ValidationOptions, callback: (err: ValidationError, value: T) => R): R;
 
 	/**
 	 * Converts literal schema definition to joi schema object (or returns the same back if already a joi schema object).