diff --git a/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallProgressFragment.kt b/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallProgressFragment.kt
index e4ee4589..447fcb3a 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallProgressFragment.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallProgressFragment.kt
@@ -15,7 +15,6 @@ import androidx.recyclerview.widget.LinearLayoutManager.VERTICAL
 import androidx.recyclerview.widget.RecyclerView
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.restore.RestoreViewModel
-import com.stevesoltys.seedvault.restore.install.ApkInstallState.QUEUED
 import org.koin.androidx.viewmodel.ext.android.sharedViewModel
 
 class InstallProgressFragment : Fragment() {
@@ -75,12 +74,11 @@ class InstallProgressFragment : Fragment() {
         // skip this screen, if there are no apps to install
         if (installResult.isEmpty()) viewModel.onNextClicked()
 
-        val result = installResult.filterValues { it.state != QUEUED }
         val position = layoutManager.findFirstVisibleItemPosition()
-        adapter.update(result.values)
+        adapter.update(installResult.getNotQueued())
         if (position == 0) layoutManager.scrollToPosition(0)
 
-        result.getInProgress()?.let {
+        installResult.getInProgress()?.let {
             progressBar.progress = it.progress
             progressBar.max = it.total
         }
diff --git a/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallResult.kt b/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallResult.kt
index 01c06729..99d968b5 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallResult.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/restore/install/InstallResult.kt
@@ -1,28 +1,66 @@
 package com.stevesoltys.seedvault.restore.install
 
 import android.graphics.drawable.Drawable
+import com.stevesoltys.seedvault.restore.install.ApkInstallState.IN_PROGRESS
+import com.stevesoltys.seedvault.restore.install.ApkInstallState.QUEUED
 import java.util.concurrent.ConcurrentHashMap
 
-internal typealias InstallResult = Map<String, ApkInstallResult>
+internal interface InstallResult {
+    /**
+     * Returns true, if there is no packages to install and false otherwise.
+     */
+    fun isEmpty(): Boolean
 
-internal fun InstallResult.getInProgress(): ApkInstallResult? {
-    val filtered = filterValues { result -> result.state == ApkInstallState.IN_PROGRESS }
-    if (filtered.isEmpty()) return null
-    check(filtered.size == 1) { "More than one package in progress: ${filtered.keys}" }
-    return filtered.values.first()
+    /**
+     * Returns the [ApkInstallResult] of the package currently [IN_PROGRESS]
+     * or null if there is no such package.
+     */
+    fun getInProgress(): ApkInstallResult?
+
+    /**
+     * Get all [ApkInstallResult]s that are not in state [QUEUED].
+     */
+    fun getNotQueued(): Collection<ApkInstallResult>
+
+    /**
+     * Get the [ApkInstallResult] for the given package name or null if none exists.
+     */
+    operator fun get(packageName: String): ApkInstallResult?
 }
 
-internal class MutableInstallResult(initialCapacity: Int) :
-    ConcurrentHashMap<String, ApkInstallResult>(initialCapacity) {
+internal class MutableInstallResult(initialCapacity: Int) : InstallResult {
+
+    private val installResults = ConcurrentHashMap<String, ApkInstallResult>(initialCapacity)
+
+    override fun isEmpty() = installResults.isEmpty()
+
+    override fun getInProgress(): ApkInstallResult? {
+        val filtered = installResults.filterValues { result -> result.state == IN_PROGRESS }
+        if (filtered.isEmpty()) return null
+        check(filtered.size == 1) { "More than one package in progress: ${filtered.keys}" }
+        return filtered.values.first()
+    }
+
+    override fun getNotQueued(): Collection<ApkInstallResult> {
+        return installResults.filterValues { result -> result.state != QUEUED }.values
+    }
+
+    override fun get(packageName: String) = installResults[packageName]
+
+    operator fun set(packageName: String, installResult: ApkInstallResult) {
+        installResults[packageName] = installResult
+    }
+
     fun update(
         packageName: String,
         updateFun: (ApkInstallResult) -> ApkInstallResult
     ): MutableInstallResult {
         val result = get(packageName)
         check(result != null) { "ApkRestoreResult for $packageName does not exist." }
-        set(packageName, updateFun(result))
+        installResults[packageName] = updateFun(result)
         return this
     }
+
 }
 
 internal data class ApkInstallResult(
diff --git a/app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkRestoreTest.kt b/app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkRestoreTest.kt
index 7cda2601..d68418dc 100644
--- a/app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkRestoreTest.kt
+++ b/app/src/test/java/com/stevesoltys/seedvault/restore/install/ApkRestoreTest.kt
@@ -167,7 +167,7 @@ internal class ApkRestoreTest : TransportTest() {
     @Test
     fun `test successful run`(@TempDir tmpDir: Path) = runBlocking {
         val installResult = MutableInstallResult(1).apply {
-            put(
+            set(
                 packageName, ApkInstallResult(
                     packageName,
                     progress = 1,
@@ -244,7 +244,7 @@ internal class ApkRestoreTest : TransportTest() {
             every { installedPackageInfo.longVersionCode } returns packageMetadata.version!! - 1
             if (!willFail) {
                 val installResult = MutableInstallResult(1).apply {
-                    put(
+                    set(
                         packageName,
                         ApkInstallResult(packageName, progress = 1, total = 1, state = SUCCEEDED)
                     )