diff --git a/mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapStore.java b/mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapStore.java
index e15b627097db053d3838fdd12f8240c3f04c58cb..b723fa9ce49486e0a7589b0e8992461f7503a1c8 100644
--- a/mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapStore.java
+++ b/mail/protocols/imap/src/main/java/com/fsck/k9/mail/store/imap/ImapStore.java
@@ -179,7 +179,7 @@ public class ImapStore extends RemoteStore {
                 ListResponse.parseLsub(responses) :
                 ListResponse.parseList(responses);
 
-        List<FolderListItem> folders = new ArrayList<>(listResponses.size());
+        Map<String, FolderListItem> folderMap = new HashMap<>(listResponses.size());
         for (ListResponse listResponse : listResponses) {
             String decodedFolderName;
             try {
@@ -235,10 +235,15 @@ public class ImapStore extends RemoteStore {
                 type = FolderType.REGULAR;
             }
 
-            folders.add(new FolderListItem(folder, type));
+            FolderListItem existingItem = folderMap.get(folder);
+            if (existingItem == null || existingItem.getType() == FolderType.REGULAR) {
+                folderMap.put(folder, new FolderListItem(folder, type));
+            }
         }
 
+        List<FolderListItem> folders = new ArrayList<>(folderMap.size() + 1);
         folders.add(new FolderListItem(ImapFolder.INBOX, FolderType.INBOX));
+        folders.addAll(folderMap.values());
 
         return folders;
     }
diff --git a/mail/protocols/imap/src/test/java/com/fsck/k9/mail/store/imap/ImapStoreTest.java b/mail/protocols/imap/src/test/java/com/fsck/k9/mail/store/imap/ImapStoreTest.java
index d7079fa16af456e873a2295b340502be28d21840..13ceadc6e5e48997bea47f0f2358b39adfaf8115 100644
--- a/mail/protocols/imap/src/test/java/com/fsck/k9/mail/store/imap/ImapStoreTest.java
+++ b/mail/protocols/imap/src/test/java/com/fsck/k9/mail/store/imap/ImapStoreTest.java
@@ -241,6 +241,31 @@ public class ImapStoreTest {
         assertEquals(Sets.newSet("INBOX", "FolderOne"), extractFolderNames(result));
     }
 
+    @Test
+    public void getPersonalNamespaces_withDuplicateFolderNames_shouldRemoveDuplicatesAndKeepFolderType()
+            throws Exception {
+        ImapConnection imapConnection = mock(ImapConnection.class);
+        when(imapConnection.hasCapability(Capabilities.LIST_EXTENDED)).thenReturn(true);
+        when(imapConnection.hasCapability(Capabilities.SPECIAL_USE)).thenReturn(true);
+        List<ImapResponse> imapResponses = Arrays.asList(
+                createImapResponse("* LIST () \".\" \"INBOX\""),
+                createImapResponse("* LIST (\\HasNoChildren) \".\" \"Junk\""),
+                createImapResponse("* LIST (\\Junk) \".\" \"Junk\""),
+                createImapResponse("* LIST (\\HasNoChildren) \".\" \"Junk\""),
+                createImapResponse("5 OK Success")
+        );
+        when(imapConnection.executeSimpleCommand("LIST \"\" \"*\" RETURN (SPECIAL-USE)")).thenReturn(imapResponses);
+        imapStore.enqueueImapConnection(imapConnection);
+
+        List<ImapFolder> result = imapStore.getPersonalNamespaces();
+
+        assertNotNull(result);
+        assertEquals(2, result.size());
+        ImapFolder junkFolder = getFolderByName(result, "Junk");
+        assertNotNull(junkFolder);
+        assertEquals(FolderType.SPAM, junkFolder.getType());
+    }
+
     @Test
     public void getPersonalNamespaces_withoutException_shouldLeaveImapConnectionOpen() throws Exception {
         ImapConnection imapConnection = mock(ImapConnection.class);
@@ -367,6 +392,15 @@ public class ImapStoreTest {
         return folderNames;
     }
 
+    private ImapFolder getFolderByName(List<ImapFolder> result, String folderName) {
+        for (ImapFolder imapFolder : result) {
+            if (imapFolder.getName().equals(folderName)) {
+                return imapFolder;
+            }
+        }
+        return null;
+    }
+
     private Map<String, ImapFolder> toFolderMap(List<ImapFolder> folders) {
         Map<String, ImapFolder> folderMap = new HashMap<>();
         for (ImapFolder folder : folders) {