diff --git a/app/src/main/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivity.kt b/app/src/main/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivity.kt
index 4d04e7e20d..864a3692ce 100644
--- a/app/src/main/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivity.kt
+++ b/app/src/main/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivity.kt
@@ -5,6 +5,7 @@
 package org.mozilla.fenix.customtabs
 
 import android.content.Intent
+import androidx.annotation.VisibleForTesting
 import androidx.navigation.NavDestination
 import androidx.navigation.NavDirections
 import kotlinx.android.synthetic.main.activity_home.*
@@ -111,16 +112,19 @@ open class ExternalAppBrowserActivity : HomeActivity() {
         }
     }
 
-    private fun hasExternalTab(): Boolean {
+    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+    internal fun hasExternalTab(): Boolean {
         return getExternalTab() != null
     }
 
-    private fun getExternalTab(): SessionState? {
+    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+    internal fun getExternalTab(): SessionState? {
         val id = getExternalTabId() ?: return null
         return components.core.store.state.findCustomTab(id)
     }
 
-    private fun getExternalTabId(): String? {
+    @VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+    internal fun getExternalTabId(): String? {
         return getIntentSessionId(SafeIntent(intent))
     }
 }
diff --git a/app/src/test/java/org/mozilla/fenix/components/toolbar/DefaultBrowserToolbarMenuControllerTest.kt b/app/src/test/java/org/mozilla/fenix/components/toolbar/DefaultBrowserToolbarMenuControllerTest.kt
index a5c2d6c314..4082077ae6 100644
--- a/app/src/test/java/org/mozilla/fenix/components/toolbar/DefaultBrowserToolbarMenuControllerTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/components/toolbar/DefaultBrowserToolbarMenuControllerTest.kt
@@ -513,7 +513,7 @@ class DefaultBrowserToolbarMenuControllerTest {
         verify { currentSession.customTabConfig = null }
         verify { sessionManager.select(currentSession) }
         verify { activity.startActivity(openInFenixIntent) }
-        verify { activity.finish() }
+        verify { activity.finishAndRemoveTask() }
     }
 
     @Test
diff --git a/app/src/test/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivityTest.kt b/app/src/test/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivityTest.kt
index 19d562c9ef..280f40e80f 100644
--- a/app/src/test/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivityTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/customtabs/ExternalAppBrowserActivityTest.kt
@@ -12,18 +12,28 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.spyk
 import io.mockk.verify
+import mozilla.components.browser.state.state.BrowserState
+import mozilla.components.browser.state.state.createCustomTab
+import mozilla.components.browser.state.state.createTab
+import mozilla.components.browser.state.store.BrowserStore
+import mozilla.components.feature.intent.ext.putSessionId
 import mozilla.components.support.utils.toSafeIntent
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertNotNull
 import org.junit.Assert.assertNull
+import org.junit.Assert.assertTrue
 import org.junit.Test
+import org.junit.runner.RunWith
 import org.mozilla.fenix.BrowserDirection
 import org.mozilla.fenix.browser.browsingmode.BrowsingMode
 import org.mozilla.fenix.browser.browsingmode.BrowsingModeManager
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.ext.components
+import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
 import org.mozilla.fenix.utils.Settings
 
+@RunWith(FenixRobolectricTestRunner::class)
 class ExternalAppBrowserActivityTest {
 
     @Test
@@ -95,4 +105,68 @@ class ExternalAppBrowserActivityTest {
         assertNull(directions)
         verify { activity.finishAndRemoveTask() }
     }
+
+    @Test
+    fun `ExternalAppBrowserActivity with matching external tab`() {
+        val store = BrowserStore(BrowserState(
+            customTabs = listOf(
+                createCustomTab(
+                    url = "https://www.mozilla.org",
+                    id = "mozilla"
+                )
+            )
+        ))
+
+        val intent = Intent(Intent.ACTION_VIEW).apply { putSessionId("mozilla") }
+
+        val activity = spyk(ExternalAppBrowserActivity())
+        every { activity.components.core.store } returns store
+        every { activity.intent } returns intent
+
+        assertTrue(activity.hasExternalTab())
+
+        assertEquals("mozilla", activity.getExternalTabId())
+
+        val tab = activity.getExternalTab()
+        assertNotNull(tab!!)
+        assertEquals("https://www.mozilla.org", tab.content.url)
+    }
+
+    @Test
+    fun `ExternalAppBrowserActivity without matching external tab`() {
+        val store = BrowserStore()
+
+        val intent = Intent(Intent.ACTION_VIEW).apply { putSessionId("mozilla") }
+
+        val activity = spyk(ExternalAppBrowserActivity())
+        every { activity.components.core.store } returns store
+        every { activity.intent } returns intent
+
+        assertFalse(activity.hasExternalTab())
+        assertEquals("mozilla", activity.getExternalTabId())
+        assertNull(activity.getExternalTab())
+    }
+
+    @Test
+    fun `ExternalAppBrowserActivity with matching regular tab`() {
+        val store = BrowserStore(BrowserState(
+            tabs = listOf(
+                createTab(
+                    url = "https://www.mozilla.org",
+                    id = "mozilla"
+                )
+            )
+        ))
+
+        val intent = Intent(Intent.ACTION_VIEW).apply { putSessionId("mozilla") }
+
+        val activity = spyk(ExternalAppBrowserActivity())
+        every { activity.components.core.store } returns store
+        every { activity.intent } returns intent
+
+        // Even though we have a matching regular tab we do not care about it in ExternalAppBrowserActivity
+        assertFalse(activity.hasExternalTab())
+        assertEquals("mozilla", activity.getExternalTabId())
+        assertNull(activity.getExternalTab())
+    }
 }