diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 8d4639f..20b43fe 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -121,6 +121,7 @@ dependencies {
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
     androidTestImplementation(libs.androidx.test.rules)
+    androidTestImplementation(libs.truth)
     androidTestImplementation(platform(libs.androidx.compose.bom))
     androidTestImplementation(libs.androidx.ui.test.junit4)
 }
diff --git a/app/src/androidTest/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositorySmokeTest.kt b/app/src/androidTest/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositorySmokeTest.kt
new file mode 100644
index 0000000..1fd3236
--- /dev/null
+++ b/app/src/androidTest/java/de/jeanlucmakiola/calendula/data/calendar/CalendarRepositorySmokeTest.kt
@@ -0,0 +1,45 @@
+package de.jeanlucmakiola.calendula.data.calendar
+
+import android.Manifest
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.rule.GrantPermissionRule
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.runBlocking
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import kotlin.time.Instant
+
+@RunWith(AndroidJUnit4::class)
+class CalendarRepositorySmokeTest {
+
+    @get:Rule
+    val permissionRule: GrantPermissionRule =
+        GrantPermissionRule.grant(Manifest.permission.READ_CALENDAR)
+
+    private val context = InstrumentationRegistry.getInstrumentation().targetContext
+
+    private fun newRepo(): CalendarRepositoryImpl {
+        val dataSource = AndroidCalendarDataSource(context)
+        return CalendarRepositoryImpl(dataSource, Dispatchers.IO)
+    }
+
+    @Test
+    fun calendars_returnsListWithoutCrashing() = runBlocking {
+        val repo = newRepo()
+        val first = repo.calendars().first()
+        assertThat(first).isNotNull()
+    }
+
+    @Test
+    fun instances_returnsListWithoutCrashing() = runBlocking {
+        val repo = newRepo()
+        val now = Instant.fromEpochMilliseconds(System.currentTimeMillis())
+        val oneDayLater = Instant.fromEpochMilliseconds(System.currentTimeMillis() + 86_400_000L)
+        val first = repo.instances(now..oneDayLater).first()
+        assertThat(first).isNotNull()
+    }
+}