diff --git a/src/lib/ws/gateway.ts b/src/lib/ws/gateway.ts
index b6c7bed5..c7e71fca 100644
--- a/src/lib/ws/gateway.ts
+++ b/src/lib/ws/gateway.ts
@@ -38,10 +38,10 @@ io
 
 		// Handlers
 		subscribeWithHandler(socket, 'probe:status:update', handleStatusUpdate(probe));
-		socket.on('probe:isIPv6Supported:update', handleIsIPv6SupportedUpdate(probe));
-		socket.on('probe:isIPv4Supported:update', handleIsIPv4SupportedUpdate(probe));
-		socket.on('probe:dns:update', handleDnsUpdate(probe));
-		socket.on('probe:stats:report', handleStatsReport(probe));
+		subscribeWithHandler(socket, 'probe:isIPv6Supported:update', handleIsIPv6SupportedUpdate(probe));
+		subscribeWithHandler(socket, 'probe:isIPv4Supported:update', handleIsIPv4SupportedUpdate(probe));
+		subscribeWithHandler(socket, 'probe:dns:update', handleDnsUpdate(probe));
+		subscribeWithHandler(socket, 'probe:stats:report', handleStatsReport(probe));
 		socket.onAnyOutgoing(listenMeasurementRequest(probe));
 		subscribeWithHandler(socket, 'probe:measurement:ack', handleMeasurementAck(probe));
 		subscribeWithHandler(socket, 'probe:measurement:progress', handleMeasurementProgress(probe));
diff --git a/src/lib/ws/helper/subscribe-handler.ts b/src/lib/ws/helper/subscribe-handler.ts
index 4dc910fd..e123a867 100644
--- a/src/lib/ws/helper/subscribe-handler.ts
+++ b/src/lib/ws/helper/subscribe-handler.ts
@@ -5,7 +5,7 @@ import type { ServerSocket } from '../server.js';
 const logger = scopedLogger('ws:handler:error');
 const isError = (error: unknown): error is Error => Boolean(error as Error['message']);
 
-type HandlerMethod = (...args: never[]) => Promise<void>;
+type HandlerMethod = (...args: never[]) => Promise<void> | void;
 
 export const subscribeWithHandler = (socket: ServerSocket, event: string, method: HandlerMethod) => {
 	socket.on(event, async (...args) => {
@@ -21,11 +21,7 @@ export const subscribeWithHandler = (socket: ServerSocket, event: string, method
 			}
 
 			if (Joi.isError(error)) {
-				const messages = error.details.map(({ message, context }) => `${message}. Received: "${context?.value}"`);
-
-				if (messages.length) {
-					details = messages.join('\n');
-				}
+				details = formatJoiError(error);
 			}
 
 			logger.info(`Event "${event}" failed to handle for (${details})`, {
@@ -36,3 +32,17 @@ export const subscribeWithHandler = (socket: ServerSocket, event: string, method
 		}
 	});
 };
+
+const formatJoiError = (error: Joi.ValidationError) => {
+	const messages = error.details.map(({ message, context }) => {
+		let str = `${message}.`;
+
+		if (context?.value) {
+			str += `Received: "${context?.value}".`;
+		}
+
+		return str;
+	});
+
+	return messages.length ? error.message : messages.join('\n');
+};
diff --git a/src/measurement/handler/progress.ts b/src/measurement/handler/progress.ts
index 5aab8cc4..73942b26 100644
--- a/src/measurement/handler/progress.ts
+++ b/src/measurement/handler/progress.ts
@@ -1,11 +1,29 @@
+import Joi from 'joi';
 import type { Probe } from '../../probe/types.js';
 import type { MeasurementProgressMessage } from '../types.js';
 import { getMeasurementRunner } from '../runner.js';
 import { getProbeValidator } from '../../lib/probe-validator.js';
 
+const schema = Joi.object<MeasurementProgressMessage>({
+	testId: Joi.string().required(),
+	measurementId: Joi.string().required(),
+	overwrite: Joi.boolean(),
+	result: Joi.object({
+		rawOutput: Joi.string().required(),
+		rawHeaders: Joi.string(),
+		rawBody: Joi.string(),
+	}).required(),
+}).required();
+
 const runner = getMeasurementRunner();
 
 export const handleMeasurementProgress = (probe: Probe) => async (data: MeasurementProgressMessage): Promise<void> => {
-	await getProbeValidator().validateProbe(data.measurementId, data.testId, probe.uuid);
-	await runner.recordProgress(data);
+	const validation = schema.validate(data);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
+	await getProbeValidator().validateProbe(validation.value.measurementId, validation.value.testId, probe.uuid);
+	await runner.recordProgress(validation.value);
 };
diff --git a/src/measurement/handler/result.ts b/src/measurement/handler/result.ts
index ca447753..7a0171f3 100644
--- a/src/measurement/handler/result.ts
+++ b/src/measurement/handler/result.ts
@@ -1,11 +1,47 @@
+import Joi from 'joi';
 import type { Probe } from '../../probe/types.js';
-import type { MeasurementResultMessage } from '../types.js';
+import type { MeasurementResultMessage, PingResult } from '../types.js';
 import { getMeasurementRunner } from '../runner.js';
 import { getProbeValidator } from '../../lib/probe-validator.js';
 
+const pingResultSchema = Joi.object<PingResult>({
+	status: Joi.string().required(),
+	rawOutput: Joi.string().required(),
+	resolvedAddress: Joi.string().required().allow(null),
+	resolvedHostname: Joi.string().required().allow(null),
+	timings: Joi.array().items(Joi.object({
+		rtt: Joi.number().required(),
+		ttl: Joi.number().required(),
+	})).required(),
+	stats: Joi.object({
+		min: Joi.number().required().allow(null),
+		max: Joi.number().required().allow(null),
+		avg: Joi.number().required().allow(null),
+		total: Joi.number().required().allow(null),
+		loss: Joi.number().required().allow(null),
+		rcv: Joi.number().required().allow(null),
+		drop: Joi.number().required().allow(null),
+	}).required(),
+});
+
+const schema = Joi.object<MeasurementResultMessage>({
+	testId: Joi.string().required(),
+	measurementId: Joi.string().required(),
+	overwrite: Joi.boolean(),
+	result: Joi.alternatives([
+		pingResultSchema,
+	]).required(),
+}).required();
+
 const runner = getMeasurementRunner();
 
 export const handleMeasurementResult = (probe: Probe) => async (data: MeasurementResultMessage): Promise<void> => {
+	const validation = schema.validate(data);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
 	await getProbeValidator().validateProbe(data.measurementId, data.testId, probe.uuid);
 	await runner.recordResult(data);
 };
diff --git a/src/measurement/types.ts b/src/measurement/types.ts
index efaeb610..b3bde808 100644
--- a/src/measurement/types.ts
+++ b/src/measurement/types.ts
@@ -20,13 +20,17 @@ type PingTiming = {
 };
 
 export type PingResult = TestResult & {
+	resolvedAddress: string | null,
+	resolvedHostname: string | null,
 	timings: PingTiming[];
 	stats: {
-		min: number;
-		avg: number;
-		max: number;
-		stddev: number;
-		packetLoss: number;
+		min: number | null,
+		max: number | null,
+		avg: number | null,
+		total: number | null,
+		loss: number | null,
+		rcv: number | null,
+		drop: number | null,
 	};
 };
 
diff --git a/src/probe/handler/dns.ts b/src/probe/handler/dns.ts
index 00719ac1..f4064e08 100644
--- a/src/probe/handler/dns.ts
+++ b/src/probe/handler/dns.ts
@@ -1,5 +1,14 @@
+import Joi from 'joi';
 import type { Probe } from '../types.js';
 
+const schema = Joi.array<string[]>().items(Joi.string()).required();
+
 export const handleDnsUpdate = (probe: Probe) => (list: string[]): void => {
-	probe.resolvers = list;
+	const validation = schema.validate(list);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
+	probe.resolvers = validation.value;
 };
diff --git a/src/probe/handler/ip-version.ts b/src/probe/handler/ip-version.ts
index 82bd0342..0d7ded4f 100644
--- a/src/probe/handler/ip-version.ts
+++ b/src/probe/handler/ip-version.ts
@@ -1,9 +1,24 @@
+import Joi from 'joi';
 import type { Probe } from '../types.js';
 
+const schema = Joi.boolean().required();
+
 export const handleIsIPv4SupportedUpdate = (probe: Probe) => (isIPv4Supported: boolean): void => {
-	probe.isIPv4Supported = isIPv4Supported;
+	const validation = schema.validate(isIPv4Supported);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
+	probe.isIPv4Supported = validation.value;
 };
 
 export const handleIsIPv6SupportedUpdate = (probe: Probe) => (isIPv6Supported: boolean): void => {
-	probe.isIPv6Supported = isIPv6Supported;
+	const validation = schema.validate(isIPv6Supported);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
+	probe.isIPv6Supported = validation.value;
 };
diff --git a/src/probe/handler/stats.ts b/src/probe/handler/stats.ts
index 39e8ab9d..6a34d79e 100644
--- a/src/probe/handler/stats.ts
+++ b/src/probe/handler/stats.ts
@@ -1,5 +1,23 @@
+import Joi from 'joi';
 import type { Probe, ProbeStats } from '../types.js';
 
+const schema = Joi.object<ProbeStats>({
+	cpu: Joi.object({
+		load: Joi.array().items(Joi.object({
+			usage: Joi.number().required(),
+		})).required(),
+	}).required(),
+	jobs: Joi.object({
+		count: Joi.number().required(),
+	}).required(),
+}).required();
+
 export const handleStatsReport = (probe: Probe) => (report: ProbeStats): void => {
-	probe.stats = report;
+	const validation = schema.validate(report);
+
+	if (validation.error) {
+		throw validation.error;
+	}
+
+	probe.stats = validation.value;
 };
diff --git a/src/probe/handler/status.ts b/src/probe/handler/status.ts
index b7e2ea1d..f4fa64a7 100644
--- a/src/probe/handler/status.ts
+++ b/src/probe/handler/status.ts
@@ -1,10 +1,10 @@
 import Joi from 'joi';
 import type { Probe } from '../types.js';
 
-const schema = Joi.string<Probe['status']>().valid('initializing', 'ready', 'unbuffer-missing', 'ping-test-failed', 'sigterm');
+const schema = Joi.string<Probe['status']>().valid('initializing', 'ready', 'unbuffer-missing', 'ping-test-failed', 'sigterm').required();
 
-export const handleStatusUpdate = (probe: Probe) => async (input: unknown) => {
-	const validation = schema.validate(input);
+export const handleStatusUpdate = (probe: Probe) => (status: Probe['status']) => {
+	const validation = schema.validate(status);
 
 	if (validation.error) {
 		throw validation.error;