diff --git a/monkey/monkey_island/cc/ui/src/components/configuration-components/ValidationFormats.js b/monkey/monkey_island/cc/ui/src/components/configuration-components/ValidationFormats.js
index d7c0a371c..bac83c9f2 100644
--- a/monkey/monkey_island/cc/ui/src/components/configuration-components/ValidationFormats.js
+++ b/monkey/monkey_island/cc/ui/src/components/configuration-components/ValidationFormats.js
@@ -9,7 +9,7 @@ const linuxPathStartsWithTildeRegex = /^~/ // path starts with `~`
 
 
 const windowsAbsolutePathRegex = /^([A-Za-z]:(\\|\/))/ // path starts like `C:\` OR `C:/`
-const windowsEnvVarNonNumeric = '[A-Za-z#\\$\'\\(\\)\\*\\+,-\\.\\?@\\[\\]_`\\{\\}~+ ]'
+const windowsEnvVarNonNumeric = '[A-Za-z#\\$\'\\(\\)\\*\\+,\\-\\.\\?@\\[\\]_`\\{\\}~+ ]'
 const windowsPathStartsWithEnvVariableRegex = new RegExp(
 	`^%(${windowsEnvVarNonNumeric}+(${windowsEnvVarNonNumeric}|\\d)*)%`
 ) // path starts like `$` OR `%abc%`