diff --git a/Ghidra/Features/GhidraServer/src/main/java/ghidra/server/Repository.java b/Ghidra/Features/GhidraServer/src/main/java/ghidra/server/Repository.java
index 927dd3f2af..95b0602692 100644
--- a/Ghidra/Features/GhidraServer/src/main/java/ghidra/server/Repository.java
+++ b/Ghidra/Features/GhidraServer/src/main/java/ghidra/server/Repository.java
@@ -357,10 +357,12 @@ public class Repository implements FileSystemListener, RepositoryLogger {
 			LinkedHashMap<String, User> newUserMap = new LinkedHashMap<>();
 			for (User user : users) {
 				String userName = user.getName();
-				if (UserManager.ANONYMOUS_USERNAME.equals(userName) ||
-					!allUsers.contains(userName)) {
+				if (UserManager.ANONYMOUS_USERNAME.equals(userName)) {
 					continue; // ignore
 				}
+				if (!allUsers.contains(userName)) {
+					throw new IOException("Unknown user specified: " + userName);
+				}
 				if (!user.hasWritePermission() && !user.isReadOnly() && !user.isAdmin()) {
 					throw new IOException("User specified with invalid permission: " + userName);
 				}
diff --git a/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/server/RepositoryTest.java b/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/server/RepositoryTest.java
index aeadceb3f3..4ada4a187a 100644
--- a/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/server/RepositoryTest.java
+++ b/Ghidra/Test/IntegrationTest/src/test.slow/java/ghidra/server/RepositoryTest.java
@@ -4,9 +4,9 @@
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- * 
+ *
  *      http://www.apache.org/licenses/LICENSE-2.0
- * 
+ *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
@@ -18,6 +18,7 @@ package ghidra.server;
 import static org.junit.Assert.*;
 
 import java.io.File;
+import java.io.IOException;
 
 import org.junit.*;
 
@@ -50,7 +51,13 @@ public class RepositoryTest extends AbstractGhidraHeadedIntegrationTest {
 		serverRoot.mkdir();
 
 		mgr = new RepositoryManager(serverRoot, false, 0, false);
-		mgr.getUserManager().addUser(userName);
+		UserManager userManager = mgr.getUserManager();
+		userManager.addUser(userName);
+
+		userManager.addUser("user-a");
+		userManager.addUser("user-b");
+		userManager.addUser("user-c");
+		userManager.addUser("user-d");
 
 		repository = mgr.createRepository(userName, REPOSITORY_NAME);
 	}
@@ -94,17 +101,10 @@ public class RepositoryTest extends AbstractGhidraHeadedIntegrationTest {
 			Assert.fail("Should not have been able to change current user's access!");
 		}
 		catch (UserAccessException e) {
+			// expected
 		}
 
-		users[3] = new User("user-x", User.ADMIN);
-		try {
-			repository.setUserList(userName, users, false);
-			Assert.fail("Should not have been able to set the user list!");
-		}
-		catch (UserAccessException e) {
-		}
-
-		users[4] = new User(userName, User.ADMIN);
+		users[4] = new User(userName, User.ADMIN); // restore current users Admin access
 		repository.setUserList(userName, users, false);
 
 		User[] reportedUsers = repository.getUserList(userName);
@@ -113,6 +113,15 @@ public class RepositoryTest extends AbstractGhidraHeadedIntegrationTest {
 			assertEquals(users[i].getName(), reportedUsers[i].getName());
 			assertEquals(users[i].getPermissionType(), reportedUsers[i].getPermissionType());
 		}
+
+		users[3] = new User("user-x", User.ADMIN);
+		try {
+			repository.setUserList(userName, users, false);
+			Assert.fail("Should not have been able to specify unknown user");
+		}
+		catch (IOException e) {
+			// expected
+		}
 	}
 
 	@Test