diff --git a/Mac/Preferences/Accounts/AccountsFeedbinWindowController.swift b/Mac/Preferences/Accounts/AccountsFeedbinWindowController.swift
index 711ab2758..e6598cd5a 100644
--- a/Mac/Preferences/Accounts/AccountsFeedbinWindowController.swift
+++ b/Mac/Preferences/Accounts/AccountsFeedbinWindowController.swift
@@ -58,6 +58,11 @@ class AccountsFeedbinWindowController: NSWindowController {
 			return
 		}
 		
+		guard !AccountManager.shared.duplicateServiceAccount(type: .feedbin, username: usernameTextField.stringValue) else {
+			self.errorMessageLabel.stringValue = NSLocalizedString("There is already a Feedbin account with that username created.", comment: "Duplicate Error")
+			return
+		}
+		
 		actionButton.isEnabled = false
 		progressIndicator.isHidden = false
 		progressIndicator.startAnimation(self)
diff --git a/Mac/Preferences/Accounts/AccountsNewsBlurWindowController.swift b/Mac/Preferences/Accounts/AccountsNewsBlurWindowController.swift
index d1b1a2bb8..723e254d1 100644
--- a/Mac/Preferences/Accounts/AccountsNewsBlurWindowController.swift
+++ b/Mac/Preferences/Accounts/AccountsNewsBlurWindowController.swift
@@ -55,7 +55,12 @@ class AccountsNewsBlurWindowController: NSWindowController {
 			self.errorMessageLabel.stringValue = NSLocalizedString("Username required.", comment: "Credentials Error")
 			return
 		}
-
+		
+		guard !AccountManager.shared.duplicateServiceAccount(type: .newsBlur, username: usernameTextField.stringValue) else {
+			self.errorMessageLabel.stringValue = NSLocalizedString("There is already a NewsBlur account with that username created.", comment: "Duplicate Error")
+			return
+		}
+		
 		actionButton.isEnabled = false
 		progressIndicator.isHidden = false
 		progressIndicator.startAnimation(self)