diff --git a/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelFlowTest.kt b/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelFlowTest.kt
index 1a7920efdc..e504817753 100644
--- a/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelFlowTest.kt
+++ b/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelFlowTest.kt
@@ -22,6 +22,7 @@ package com.vitorpamplona.amethyst.calendar
 
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.ViewModelStore
+import androidx.lifecycle.viewModelScope
 import com.vitorpamplona.amethyst.commons.feeds.FeedContentState
 import com.vitorpamplona.amethyst.commons.model.AddressableNote
 import com.vitorpamplona.amethyst.commons.model.cache.LocalCache
@@ -33,13 +34,16 @@ import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarEvent
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.cancel
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.job
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.test.resetMain
 import kotlinx.coroutines.test.setMain
+import kotlinx.coroutines.withTimeout
 import kotlinx.coroutines.withTimeoutOrNull
 import org.junit.After
 import org.junit.Assert.assertEquals
@@ -137,14 +141,20 @@ class CalendarsViewModelFlowTest {
     ) = runBlocking {
         val scope = CoroutineScope(Dispatchers.Default + SupervisorJob())
         val store = ViewModelStore()
+        var modelScope: Job? = null
         try {
             val feed = FeedContentState(CalendarAppointmentsFeedFilter(seeEverythingAccount()), scope, LocalCache)
             val model = ViewModelProvider(store, ViewModelProvider.NewInstanceFactory())[CalendarsViewModel::class.java]
+            modelScope = model.viewModelScope.coroutineContext.job
             model.init(pubKey, feed)
             block(model)
         } finally {
             store.clear()
             scope.cancel()
+            // Clearing only requests cancellation. The flowOn producers on Dispatchers.Default can
+            // still be finishing and hand their completion back to the Main collectors; wait for
+            // them here, while setMain is still in force, not after tearDown's resetMain.
+            withTimeout(AWAIT_MS) { modelScope?.join() }
         }
     }
 
diff --git a/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelTest.kt b/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelTest.kt
index 770e0add94..1358a9f67d 100644
--- a/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelTest.kt
+++ b/amethyst/src/test/java/com/vitorpamplona/amethyst/calendar/CalendarsViewModelTest.kt
@@ -22,13 +22,19 @@ package com.vitorpamplona.amethyst.calendar
 
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.ViewModelStore
+import androidx.lifecycle.viewModelScope
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.CalendarsViewMode
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.CalendarsViewModel
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.calendars.startOfWeek
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.job
+import kotlinx.coroutines.joinAll
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.test.resetMain
 import kotlinx.coroutines.test.setMain
+import kotlinx.coroutines.withTimeout
 import org.junit.After
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNull
@@ -58,13 +64,24 @@ class CalendarsViewModelTest {
         store = ViewModelStore()
     }
 
+    private val scopes = mutableListOf<Job>()
+
     @After
     fun tearDown() {
         store.clear()
+        // Clearing only requests cancellation: a producer the model runs on Dispatchers.Default
+        // (its flowOn) can still be finishing, and it hands its completion back to the Main
+        // collector. Waiting for the scopes keeps that inside setMain, instead of throwing onto a
+        // background thread after resetMain and failing whichever runTest starts next.
+        runBlocking { withTimeout(SCOPE_CLOSE_MS) { scopes.joinAll() } }
+        scopes.clear()
         Dispatchers.resetMain()
     }
 
-    private fun newModel(): CalendarsViewModel = ViewModelProvider(store, ViewModelProvider.NewInstanceFactory())[CalendarsViewModel::class.java]
+    private fun newModel(): CalendarsViewModel =
+        ViewModelProvider(store, ViewModelProvider.NewInstanceFactory())[CalendarsViewModel::class.java].also {
+            scopes += it.viewModelScope.coroutineContext.job
+        }
 
     @Test
     fun aFreshScreenOpensOnToday() {
@@ -148,4 +165,8 @@ class CalendarsViewModelTest {
 
         assertEquals("the lenses must not share one scroll offset", 4, states.distinct().size)
     }
+
+    companion object {
+        private const val SCOPE_CLOSE_MS = 5_000L
+    }
 }