diff --git a/app/src/main/java/org/tasks/caldav/CaldavCalendarSettingsActivity.kt b/app/src/main/java/org/tasks/caldav/CaldavCalendarSettingsActivity.kt
index a056343e4..7bcaf1958 100644
--- a/app/src/main/java/org/tasks/caldav/CaldavCalendarSettingsActivity.kt
+++ b/app/src/main/java/org/tasks/caldav/CaldavCalendarSettingsActivity.kt
@@ -15,7 +15,6 @@ import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.res.stringResource
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.lifecycleScope
@@ -35,7 +34,6 @@ import org.tasks.data.entity.CaldavAccount.Companion.SERVER_TASKS
 import org.tasks.data.entity.CaldavCalendar
 import org.tasks.data.entity.CaldavCalendar.Companion.ACCESS_OWNER
 import org.tasks.themes.TasksTheme
-import org.tasks.themes.colorOn
 import javax.inject.Inject
 
 @AndroidEntryPoint
@@ -72,7 +70,7 @@ class CaldavCalendarSettingsActivity : BaseCaldavCalendarSettingsActivity() {
                             val openDialog = rememberSaveable { mutableStateOf(false) }
                             ShareInviteDialog(
                                 openDialog,
-                                email = caldavAccount.serverType != SERVER_OWNCLOUD
+                                email = caldavAccount.serverType !in listOf(SERVER_OWNCLOUD, SERVER_NEXTCLOUD),
                             ) { input ->
                                 lifecycleScope.launch {
                                     share(input)
diff --git a/app/src/main/java/org/tasks/caldav/CaldavCalendarViewModel.kt b/app/src/main/java/org/tasks/caldav/CaldavCalendarViewModel.kt
index b6b4ce3a7..64f0ca883 100644
--- a/app/src/main/java/org/tasks/caldav/CaldavCalendarViewModel.kt
+++ b/app/src/main/java/org/tasks/caldav/CaldavCalendarViewModel.kt
@@ -12,6 +12,8 @@ import org.tasks.data.UUIDHelper
 import org.tasks.data.dao.CaldavDao
 import org.tasks.data.dao.PrincipalDao
 import org.tasks.data.entity.CaldavAccount
+import org.tasks.data.entity.CaldavAccount.Companion.SERVER_NEXTCLOUD
+import org.tasks.data.entity.CaldavAccount.Companion.SERVER_OWNCLOUD
 import org.tasks.data.entity.CaldavCalendar
 import org.tasks.data.entity.CaldavCalendar.Companion.ACCESS_READ_WRITE
 import org.tasks.data.entity.CaldavCalendar.Companion.INVITE_UNKNOWN
@@ -96,10 +98,10 @@ class CaldavCalendarViewModel @Inject constructor(
         list: CaldavCalendar,
         input: String
     ) = doRequest {
-        val href = if (account.serverType == CaldavAccount.SERVER_OWNCLOUD)
-            "principal:principals/users/$input"
-        else
-            "mailto:$input"
+        val href = when (account.serverType) {
+            SERVER_OWNCLOUD, SERVER_NEXTCLOUD -> "principal:principals/users/$input"
+            else -> "mailto:$input"
+        }
         withContext(Dispatchers.IO) {
             provider.forAccount(account, list.url!!).share(account, href)
         }
diff --git a/app/src/main/java/org/tasks/caldav/CaldavClient.kt b/app/src/main/java/org/tasks/caldav/CaldavClient.kt
index ecc2ed6cb..3e14bc1b8 100644
--- a/app/src/main/java/org/tasks/caldav/CaldavClient.kt
+++ b/app/src/main/java/org/tasks/caldav/CaldavClient.kt
@@ -225,8 +225,8 @@ open class CaldavClient(
         href: String,
     ) {
         when (account.serverType) {
-            SERVER_TASKS, SERVER_SABREDAV, SERVER_NEXTCLOUD -> shareSabredav(href)
-            SERVER_OWNCLOUD -> shareOwncloud(href)
+            SERVER_TASKS, SERVER_SABREDAV -> shareSabredav(href)
+            SERVER_OWNCLOUD, SERVER_NEXTCLOUD -> shareOwncloud(href)
             else -> throw IllegalArgumentException()
         }
     }
@@ -265,8 +265,8 @@ open class CaldavClient(
         href: String,
     ) {
         when (account.serverType) {
-            SERVER_TASKS, SERVER_SABREDAV, SERVER_NEXTCLOUD -> removeSabrePrincipal(calendar, href)
-            SERVER_OWNCLOUD -> removeOwncloudPrincipal(calendar, href)
+            SERVER_TASKS, SERVER_SABREDAV -> removeSabrePrincipal(calendar, href)
+            SERVER_OWNCLOUD, SERVER_NEXTCLOUD -> removeOwncloudPrincipal(calendar, href)
             else -> throw IllegalArgumentException()
         }
     }
diff --git a/app/src/main/java/org/tasks/caldav/CaldavSynchronizer.kt b/app/src/main/java/org/tasks/caldav/CaldavSynchronizer.kt
index 0e8024485..e30b8cdfb 100644
--- a/app/src/main/java/org/tasks/caldav/CaldavSynchronizer.kt
+++ b/app/src/main/java/org/tasks/caldav/CaldavSynchronizer.kt
@@ -56,6 +56,7 @@ import org.tasks.data.dao.CaldavDao
 import org.tasks.data.dao.PrincipalDao
 import org.tasks.data.entity.CaldavAccount
 import org.tasks.data.entity.CaldavAccount.Companion.ERROR_UNAUTHORIZED
+import org.tasks.data.entity.CaldavAccount.Companion.SERVER_NEXTCLOUD
 import org.tasks.data.entity.CaldavAccount.Companion.SERVER_OPEN_XCHANGE
 import org.tasks.data.entity.CaldavAccount.Companion.SERVER_OWNCLOUD
 import org.tasks.data.entity.CaldavAccount.Companion.SERVER_SABREDAV
@@ -203,7 +204,11 @@ class CaldavSynchronizer @Inject constructor(
 
     private fun getServerType(account: CaldavAccount, headers: Headers) = when {
         account.isTasksOrg -> SERVER_TASKS
-        headers["DAV"]?.contains("oc-resource-sharing") == true -> SERVER_OWNCLOUD
+        headers["DAV"]?.contains("oc-resource-sharing") == true ->
+            if (headers["DAV"]?.let { it.contains("nextcloud-") || it.contains("nc-") } == true)
+                SERVER_NEXTCLOUD
+            else
+                SERVER_OWNCLOUD
         headers["x-sabre-version"]?.isNotBlank() == true -> SERVER_SABREDAV
         headers["server"] == "Openexchange WebDAV" -> SERVER_OPEN_XCHANGE
         else -> SERVER_UNKNOWN