diff --git a/app/src/full/java/com/topjohnwu/magisk/FlashActivity.java b/app/src/full/java/com/topjohnwu/magisk/FlashActivity.java
index d5db8075e..1f8258a77 100644
--- a/app/src/full/java/com/topjohnwu/magisk/FlashActivity.java
+++ b/app/src/full/java/com/topjohnwu/magisk/FlashActivity.java
@@ -19,7 +19,6 @@ import com.topjohnwu.core.utils.Utils;
 import com.topjohnwu.magisk.components.BaseActivity;
 import com.topjohnwu.superuser.CallbackList;
 import com.topjohnwu.superuser.Shell;
-import com.topjohnwu.superuser.ShellUtils;
 
 import java.io.File;
 import java.io.FileWriter;
@@ -211,13 +210,7 @@ public class FlashActivity extends BaseActivity {
 
         @Override
         protected boolean operations() {
-            console.add("- Detecting target image");
-            srcBoot = ShellUtils.fastCmd("find_boot_image", "echo \"$BOOTIMAGE\"");
-            if (srcBoot.isEmpty()) {
-                console.add("! Unable to detect target image");
-                return false;
-            }
-            return extractZip() && patchBoot() && flashBoot();
+            return findImage() && extractZip() && patchBoot() && flashBoot();
         }
     }
 
@@ -225,21 +218,7 @@ public class FlashActivity extends BaseActivity {
 
         @Override
         protected boolean operations() {
-            String slot = ShellUtils.fastCmd("echo $SLOT");
-            String target = (TextUtils.equals(slot, "_a") ? "_b" : "_a");
-            console.add("- Target slot: " + target);
-            console.add("- Detecting target image");
-            srcBoot = ShellUtils.fastCmd(
-                    "SLOT=" + target,
-                    "find_boot_image",
-                    "SLOT=" + slot,
-                    "echo \"$BOOTIMAGE\""
-            );
-            if (srcBoot.isEmpty()) {
-                console.add("! Unable to detect target image");
-                return false;
-            }
-            return extractZip() && patchBoot() && flashBoot() && postOTA();
+            return findSecondaryImage() && extractZip() && patchBoot() && flashBoot() && postOTA();
         }
     }
 
diff --git a/core/src/main/java/com/topjohnwu/core/tasks/MagiskInstaller.java b/core/src/main/java/com/topjohnwu/core/tasks/MagiskInstaller.java
index 256efed34..dd1241d65 100644
--- a/core/src/main/java/com/topjohnwu/core/tasks/MagiskInstaller.java
+++ b/core/src/main/java/com/topjohnwu/core/tasks/MagiskInstaller.java
@@ -79,6 +79,34 @@ public abstract class MagiskInstaller {
         installDir.mkdirs();
     }
 
+    protected boolean findImage() {
+        console.add("- Detecting target image");
+        srcBoot = ShellUtils.fastCmd("find_boot_image", "echo \"$BOOTIMAGE\"");
+        if (srcBoot.isEmpty()) {
+            console.add("! Unable to detect target image");
+            return false;
+        }
+        return true;
+    }
+
+    protected boolean findSecondaryImage() {
+        String slot = ShellUtils.fastCmd("echo $SLOT");
+        String target = (TextUtils.equals(slot, "_a") ? "_b" : "_a");
+        console.add("- Target slot: " + target);
+        console.add("- Detecting target image");
+        srcBoot = ShellUtils.fastCmd(
+                "SLOT=" + target,
+                "find_boot_image",
+                "SLOT=" + slot,
+                "echo \"$BOOTIMAGE\""
+        );
+        if (srcBoot.isEmpty()) {
+            console.add("! Unable to detect target image");
+            return false;
+        }
+        return true;
+    }
+
     protected boolean extractZip() {
         String arch;
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {