diff --git a/app/src/main/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactory.kt b/app/src/main/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactory.kt
index a3c14e6..0e7499d 100644
--- a/app/src/main/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactory.kt
+++ b/app/src/main/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactory.kt
@@ -4,6 +4,7 @@ import androidx.paging.PagingSource
 import gq.kirmanak.mealient.data.recipes.db.RecipeStorage
 import gq.kirmanak.mealient.data.recipes.db.entity.RecipeSummaryEntity
 import timber.log.Timber
+import java.util.concurrent.ConcurrentSkipListSet
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -11,9 +12,9 @@ import javax.inject.Singleton
 class RecipePagingSourceFactory @Inject constructor(
     private val recipeStorage: RecipeStorage
 ) : () -> PagingSource<Int, RecipeSummaryEntity> {
-    private val sources: MutableList<PagingSource<Int, RecipeSummaryEntity>> = mutableListOf()
+    private val sources: MutableSet<PagingSource<Int, RecipeSummaryEntity>> =
+        ConcurrentSkipListSet(PagingSourceComparator)
 
-    @Synchronized
     override fun invoke(): PagingSource<Int, RecipeSummaryEntity> {
         Timber.v("invoke() called")
         val newSource = recipeStorage.queryRecipes()
@@ -21,7 +22,6 @@ class RecipePagingSourceFactory @Inject constructor(
         return newSource
     }
 
-    @Synchronized
     fun invalidate() {
         Timber.v("invalidate() called")
         for (source in sources) {
@@ -31,4 +31,15 @@ class RecipePagingSourceFactory @Inject constructor(
         }
         sources.removeAll { it.invalid }
     }
+
+    private object PagingSourceComparator : Comparator<PagingSource<Int, RecipeSummaryEntity>> {
+        override fun compare(
+            left: PagingSource<Int, RecipeSummaryEntity>?,
+            right: PagingSource<Int, RecipeSummaryEntity>?
+        ): Int {
+            val leftHash = left?.hashCode() ?: 0
+            val rightHash = right?.hashCode() ?: 0
+            return leftHash - rightHash
+        }
+    }
 }
\ No newline at end of file
diff --git a/app/src/test/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactoryTest.kt b/app/src/test/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactoryTest.kt
new file mode 100644
index 0000000..8c98a32
--- /dev/null
+++ b/app/src/test/java/gq/kirmanak/mealient/data/recipes/impl/RecipePagingSourceFactoryTest.kt
@@ -0,0 +1,35 @@
+package gq.kirmanak.mealient.data.recipes.impl
+
+import dagger.hilt.android.testing.HiltAndroidTest
+import gq.kirmanak.mealient.data.recipes.db.RecipeStorage
+import gq.kirmanak.mealient.test.HiltRobolectricTest
+import kotlinx.coroutines.*
+import org.junit.Before
+import org.junit.Test
+import javax.inject.Inject
+
+@ExperimentalCoroutinesApi
+@HiltAndroidTest
+class RecipePagingSourceFactoryTest : HiltRobolectricTest() {
+    @Inject
+    lateinit var storage: RecipeStorage
+    lateinit var subject: RecipePagingSourceFactory
+
+    @Before
+    fun setUp() {
+        subject = RecipePagingSourceFactory(storage)
+    }
+
+    @Test
+    fun `when modifying concurrently then doesn't throw`(): Unit = runBlocking {
+        (0..100).map {
+            async(Dispatchers.Default) {
+                for (i in 0..100) {
+                    subject.invalidate()
+                    subject.invoke()
+                }
+            }
+        }.awaitAll()
+    }
+
+}
\ No newline at end of file