diff --git a/client/src/Validation/validation.js b/client/src/Validation/validation.js
index 887e4e487..7676d65d8 100644
--- a/client/src/Validation/validation.js
+++ b/client/src/Validation/validation.js
@@ -130,7 +130,7 @@ const monitorValidation = joi.object({
 			.custom((value, helpers) => {
 				const noProtocol = value.replace(/^(https?:\/\/)/, "");
 
-				if (/^[a-zA-Z0-9.-]+(:\d{1,5})?$/.test(noProtocol)) {
+				if (/^[a-zA-Z0-9]([a-zA-Z0-9.-]*[a-zA-Z0-9])?(:\d{1,5})?$/.test(noProtocol)) {
 					return value;
 				}
 
diff --git a/server/validation/joi.js b/server/validation/joi.js
index 8549d470a..3fb652736 100755
--- a/server/validation/joi.js
+++ b/server/validation/joi.js
@@ -174,7 +174,7 @@ const createMonitorBodyValidation = joi.object({
 		.custom((value, helpers) => {
 			const noProtocol = value.replace(/^(https?:\/\/)/, "");
 
-			if (/^[a-zA-Z0-9.-]+(:\d{1,5})?$/.test(noProtocol)) {
+			if (/^[a-zA-Z0-9]([a-zA-Z0-9.-]*[a-zA-Z0-9])?(:\d{1,5})?$/.test(noProtocol)) {
 				return value;
 			}