diff --git a/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java b/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java
index 8aa02d42a..8d905dcc1 100644
--- a/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java
+++ b/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java
@@ -4,6 +4,7 @@ import org.briarproject.bramble.BrambleAndroidModule;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.briar.BriarCoreModule;
+import org.briarproject.briar.android.attachment.AttachmentModule;
 import org.briarproject.briar.android.navdrawer.NavDrawerActivityTest;
 
 import javax.inject.Singleton;
@@ -13,6 +14,7 @@ import dagger.Component;
 @Singleton
 @Component(modules = {
 		AppModule.class,
+		AttachmentModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,
 		BriarAccountModule.class,
diff --git a/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java b/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java
index 520042a84..29a0ecab5 100644
--- a/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java
+++ b/briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java
@@ -47,9 +47,10 @@ public class AttachmentRetrieverIntegrationTest {
 	);
 	private final MessageId msgId = new MessageId(getRandomId());
 
+	private final ImageHelper imageHelper = new ImageHelperImpl();
 	private final AttachmentRetriever retriever =
-			new AttachmentRetrieverImpl(null, dimensions,
-					new ImageHelperImpl());
+			new AttachmentRetrieverImpl(null, dimensions, imageHelper,
+					new ImageSizeCalculator(imageHelper));
 
 	@Test
 	public void testSmallJpegImage() throws Exception {
diff --git a/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java b/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java
index c8281f427..2bef6e519 100644
--- a/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java
+++ b/briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java
@@ -39,10 +39,11 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 
 	@Inject
 	AttachmentRetrieverImpl(MessagingManager messagingManager,
-			AttachmentDimensions dimensions, ImageHelper imageHelper) {
+			AttachmentDimensions dimensions, ImageHelper imageHelper,
+			ImageSizeCalculator imageSizeCalculator) {
 		this.messagingManager = messagingManager;
 		this.imageHelper = imageHelper;
-		imageSizeCalculator = new ImageSizeCalculator(imageHelper);
+		this.imageSizeCalculator = imageSizeCalculator;
 		defaultSize = dimensions.defaultSize;
 		minWidth = dimensions.minWidth;
 		maxWidth = dimensions.maxWidth;
diff --git a/briar-android/src/test/java/org/briarproject/briar/android/attachment/AttachmentRetrieverTest.java b/briar-android/src/test/java/org/briarproject/briar/android/attachment/AttachmentRetrieverTest.java
index 7a3fd9468..4558c2ff8 100644
--- a/briar-android/src/test/java/org/briarproject/briar/android/attachment/AttachmentRetrieverTest.java
+++ b/briar-android/src/test/java/org/briarproject/briar/android/attachment/AttachmentRetrieverTest.java
@@ -2,11 +2,11 @@ package org.briarproject.briar.android.attachment;
 
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.test.BrambleMockTestCase;
-import org.briarproject.briar.android.attachment.ImageHelper.DecodeResult;
 import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.jmock.Expectations;
+import org.jmock.lib.legacy.ClassImposteriser;
 import org.junit.Test;
 
 import java.io.ByteArrayInputStream;
@@ -24,14 +24,18 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 			100, 50, 200, 75, 300
 	);
 	private final MessageId msgId = new MessageId(getRandomId());
-	private final MessagingManager messagingManager =
-			context.mock(MessagingManager.class);
 	private final ImageHelper imageHelper = context.mock(ImageHelper.class);
-	private final AttachmentRetriever retriever = new AttachmentRetrieverImpl(
-			messagingManager,
-			dimensions,
-			imageHelper
-	);
+	private final ImageSizeCalculator imageSizeCalculator;
+	private final AttachmentRetriever retriever;
+
+	public AttachmentRetrieverTest() {
+		context.setImposteriser(ClassImposteriser.INSTANCE);
+		MessagingManager messagingManager =
+				context.mock(MessagingManager.class);
+		imageSizeCalculator = context.mock(ImageSizeCalculator.class);
+		retriever = new AttachmentRetrieverImpl(messagingManager, dimensions,
+				imageHelper, imageSizeCalculator);
+	}
 
 	@Test
 	public void testNoSize() {
@@ -69,8 +73,9 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 		Attachment attachment = getAttachment(mimeType);
 
 		context.checking(new Expectations() {{
-			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
-			will(returnValue(new DecodeResult(160, 240, mimeType)));
+			oneOf(imageSizeCalculator).getSize(with(any(InputStream.class)),
+					with(mimeType));
+			will(returnValue(new Size(160, 240, mimeType)));
 			oneOf(imageHelper).getExtensionFromMimeType(mimeType);
 			will(returnValue("jpg"));
 		}});
@@ -92,8 +97,9 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 		Attachment attachment = getAttachment(mimeType);
 
 		context.checking(new Expectations() {{
-			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
-			will(returnValue(new DecodeResult(1728, 2592, mimeType)));
+			oneOf(imageSizeCalculator).getSize(with(any(InputStream.class)),
+					with(mimeType));
+			will(returnValue(new Size(1728, 2592, mimeType)));
 			oneOf(imageHelper).getExtensionFromMimeType(mimeType);
 			will(returnValue("jpg"));
 		}});
@@ -108,11 +114,13 @@ public class AttachmentRetrieverTest extends BrambleMockTestCase {
 
 	@Test
 	public void testMalformedError() {
-		Attachment attachment = getAttachment("image/jpeg");
+		String mimeType = "image/jpeg";
+		Attachment attachment = getAttachment(mimeType);
 
 		context.checking(new Expectations() {{
-			oneOf(imageHelper).decodeStream(with(any(InputStream.class)));
-			will(returnValue(new DecodeResult(0, 0, "")));
+			oneOf(imageSizeCalculator).getSize(with(any(InputStream.class)),
+					with(mimeType));
+			will(returnValue(new Size()));
 			oneOf(imageHelper).getExtensionFromMimeType("");
 			will(returnValue(null));
 		}});