diff --git a/app/src/main/java/info/nightscout/androidaps/plugins/general/maintenance/ImportExportPrefs.kt b/app/src/main/java/info/nightscout/androidaps/plugins/general/maintenance/ImportExportPrefs.kt
index d90de7a086..74abd439f8 100644
--- a/app/src/main/java/info/nightscout/androidaps/plugins/general/maintenance/ImportExportPrefs.kt
+++ b/app/src/main/java/info/nightscout/androidaps/plugins/general/maintenance/ImportExportPrefs.kt
@@ -130,6 +130,15 @@ class ImportExportPrefs @Inject constructor(
         })
     }
 
+    private fun askForEncryptionPass(activity: Activity, @StringRes canceledMsg: Int, @StringRes passwordName: Int, @StringRes passwordExplanation: Int?,
+                                     @StringRes passwordWarning: Int?, then: ((password: String) -> Unit)) {
+        passwordCheck.queryAnyPassword(activity, passwordName, R.string.key_master_password, passwordExplanation, passwordWarning, { password ->
+            then(password)
+        }, {
+            ToastUtils.warnToast(activity, resourceHelper.gs(canceledMsg))
+        })
+    }
+
     private fun askForMasterPassIfNeeded(activity: Activity, @StringRes canceledMsg: Int, then: ((password: String) -> Unit)) {
         if (prefsEncryptionIsDisabled()) {
             then("")
@@ -182,6 +191,28 @@ class ImportExportPrefs @Inject constructor(
         }
     }
 
+    private fun promptForDecryptionPasswordIfNeeded(activity: Activity, prefs: Prefs, importOk: Boolean,
+                                                    format: PrefsFormat, importFile: PrefsFile, then: ((prefs: Prefs, importOk: Boolean) -> Unit)) {
+
+        // current master password was not the one used for decryption, so we prompt for old password...
+        if (!importOk && (prefs.metadata[PrefsMetadataKey.ENCRYPTION]?.status == PrefsStatus.ERROR)) {
+            askForEncryptionPass(activity, R.string.preferences_import_canceled, R.string.old_master_password,
+                R.string.different_password_used, R.string.master_password_will_be_replaced) { password ->
+
+                // ...and use it to load & decrypt file again
+                val prefsReloaded = format.loadPreferences(importFile.file, password)
+                prefsReloaded.metadata = prefFileList.checkMetadata(prefsReloaded.metadata)
+
+                // import is OK when we do not have errors (warnings are allowed)
+                val importOkCheckedAgain = checkIfImportIsOk(prefsReloaded)
+
+                then(prefsReloaded, importOkCheckedAgain);
+            }
+        } else {
+            then(prefs, importOk);
+        }
+    }
+
     private fun exportSharedPreferences(activity: Activity) {
 
         prefFileList.ensureExportDirExists()
@@ -258,32 +289,36 @@ class ImportExportPrefs @Inject constructor(
 
             try {
 
-                val prefs = format.loadPreferences(importFile.file, password)
-                prefs.metadata = prefFileList.checkMetadata(prefs.metadata)
+                val prefsAttempted = format.loadPreferences(importFile.file, password)
+                prefsAttempted.metadata = prefFileList.checkMetadata(prefsAttempted.metadata)
 
                 // import is OK when we do not have errors (warnings are allowed)
-                val importOk = checkIfImportIsOk(prefs)
+                val importOkAttempted = checkIfImportIsOk(prefsAttempted)
 
-                // if at end we allow to import preferences
-                val importPossible = (importOk || buildHelper.isEngineeringMode()) && (prefs.values.size > 0)
+                promptForDecryptionPasswordIfNeeded(activity, prefsAttempted, importOkAttempted, format, importFile) { prefs, importOk ->
 
-                PrefImportSummaryDialog.showSummary(activity, importOk, importPossible, prefs, {
-                    if (importPossible) {
-                        sp.clear()
-                        for ((key, value) in prefs.values) {
-                            if (value == "true" || value == "false") {
-                                sp.putBoolean(key, value.toBoolean())
-                            } else {
-                                sp.putString(key, value)
+                    // if at end we allow to import preferences
+                    val importPossible = (importOk || buildHelper.isEngineeringMode()) && (prefs.values.size > 0)
+
+                    PrefImportSummaryDialog.showSummary(activity, importOk, importPossible, prefs, {
+                        if (importPossible) {
+                            sp.clear()
+                            for ((key, value) in prefs.values) {
+                                if (value == "true" || value == "false") {
+                                    sp.putBoolean(key, value.toBoolean())
+                                } else {
+                                    sp.putString(key, value)
+                                }
                             }
-                        }
 
-                        restartAppAfterImport(activity)
-                    } else {
-                        // for impossible imports it should not be called
-                        ToastUtils.errorToast(activity, resourceHelper.gs(R.string.preferences_import_impossible))
-                    }
-                })
+                            restartAppAfterImport(activity)
+                        } else {
+                            // for impossible imports it should not be called
+                            ToastUtils.errorToast(activity, resourceHelper.gs(R.string.preferences_import_impossible))
+                        }
+                    })
+
+                }
 
             } catch (e: PrefFileNotFoundError) {
                 ToastUtils.errorToast(activity, resourceHelper.gs(R.string.filenotfound) + " " + importFile)
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 17343701cf..e54109587d 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -208,6 +208,9 @@
     <string name="preferences_import_canceled">Import canceled! Preferences were NOT imported!</string>
     <string name="preferences_import_impossible">Cannot import preferences!</string>
     <string name="goto_main_try_again">Please go back to main screen and try again.</string>
+    <string name="old_master_password">Old Master Password</string>
+    <string name="different_password_used">This file was exported and encrypted with different master password. Provide old master password to decrypt file.</string>
+    <string name="master_password_will_be_replaced">As a result of successful import current master password WILL BE REPLACED with that old master password!</string>
 
     <string name="preferences_import_list_title">Select file to import</string>
 
diff --git a/core/src/main/java/info/nightscout/androidaps/utils/protection/PasswordCheck.kt b/core/src/main/java/info/nightscout/androidaps/utils/protection/PasswordCheck.kt
index 04399eb95f..efc3f6dfb1 100644
--- a/core/src/main/java/info/nightscout/androidaps/utils/protection/PasswordCheck.kt
+++ b/core/src/main/java/info/nightscout/androidaps/utils/protection/PasswordCheck.kt
@@ -6,6 +6,7 @@ import android.os.Build
 import android.view.LayoutInflater
 import android.view.View
 import android.widget.EditText
+import android.widget.TextView
 import androidx.annotation.StringRes
 import info.nightscout.androidaps.core.R
 import info.nightscout.androidaps.utils.CryptoUtil
@@ -24,6 +25,9 @@ class PasswordCheck @Inject constructor(
     private val cryptoUtil: CryptoUtil
 ) {
 
+    /**
+    Asks for "managed" kind of password, checking if it is valid.
+     */
     @SuppressLint("InflateParams")
     fun queryPassword(context: Context, @StringRes labelId: Int, @StringRes preference: Int, ok: ((String) -> Unit)?, cancel: (() -> Unit)? = null, fail: (() -> Unit)? = null) {
         val password = sp.getString(preference, "")
@@ -115,4 +119,51 @@ class PasswordCheck @Inject constructor(
 
         alertDialogBuilder.create().show()
     }
+
+    /**
+    Prompt free-form password, with additional help and warning messages.
+    Preference ID (preference) is used only to generate ID for password managers,
+    since this query does NOT check validity of password.
+     */
+    @SuppressLint("InflateParams")
+    fun queryAnyPassword(context: Context, @StringRes labelId: Int, @StringRes preference: Int, @StringRes passwordExplanation: Int?,
+                         @StringRes passwordWarning: Int?, ok: ((String) -> Unit)?, cancel: (() -> Unit)? = null) {
+
+        val promptsView = LayoutInflater.from(context).inflate(R.layout.passwordprompt, null)
+        val alertDialogBuilder = AlertDialogHelper.Builder(context)
+        alertDialogBuilder.setView(promptsView)
+        passwordExplanation?.let { alertDialogBuilder.setMessage(it) }
+
+        passwordWarning?.let {
+            val extraWarning: TextView = promptsView.findViewById<View>(R.id.password_prompt_extra_message) as TextView;
+            extraWarning.text = context.getString(it);
+            extraWarning.visibility = View.VISIBLE;
+        }
+
+        val userInput = promptsView.findViewById<View>(R.id.password_prompt_pass) as EditText
+        val userInput2 = promptsView.findViewById<View>(R.id.password_prompt_pass_confirm) as EditText
+
+        userInput2.visibility = View.GONE
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val autoFillHintPasswordKind = context.getString(preference)
+            userInput.setAutofillHints(View.AUTOFILL_HINT_PASSWORD, "aaps_${autoFillHintPasswordKind}")
+            userInput.importantForAutofill = View.IMPORTANT_FOR_AUTOFILL_YES
+        }
+
+        alertDialogBuilder
+            .setCancelable(false)
+            .setCustomTitle(AlertDialogHelper.buildCustomTitle(context, context.getString(labelId), R.drawable.ic_header_key))
+            .setPositiveButton(context.getString(R.string.ok)) { _, _ ->
+                val enteredPassword = userInput.text.toString()
+                ok?.invoke(enteredPassword)
+            }
+            .setNegativeButton(context.getString(R.string.cancel)
+            ) { dialog, _ ->
+                cancel?.invoke()
+                dialog.cancel()
+            }
+
+        alertDialogBuilder.create().show()
+    }
 }
diff --git a/core/src/main/res/layout/passwordprompt.xml b/core/src/main/res/layout/passwordprompt.xml
index e363256be9..90b14b14e4 100644
--- a/core/src/main/res/layout/passwordprompt.xml
+++ b/core/src/main/res/layout/passwordprompt.xml
@@ -5,6 +5,18 @@
     android:orientation="vertical"
     android:padding="10dp">
 
+    <TextView
+        android:id="@+id/password_prompt_extra_message"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="10dp"
+        android:paddingStart="10dp"
+        android:paddingEnd="10dp"
+        android:textAppearance="?android:attr/textAppearanceSmall"
+        android:textColor="@color/warningAccentText"
+        android:visibility="gone"
+        />
+
     <EditText
         android:id="@+id/password_prompt_pass"
         android:layout_width="match_parent"
diff --git a/core/src/main/res/values/colors.xml b/core/src/main/res/values/colors.xml
index d6def91fd7..1995c932be 100644
--- a/core/src/main/res/values/colors.xml
+++ b/core/src/main/res/values/colors.xml
@@ -21,6 +21,7 @@
     <color name="dialog_title_icon_tint">#FFFFFF</color>
     <color name="warningAlertBackground">#FFFB8C00</color>
     <color name="warningAlertHeaderText">#FF000000</color>
+    <color name="warningAccentText">#FFFB8C00</color>
     <color name="errorAlertBackground">#FFFF5555</color>
     <color name="errorAlertHeaderText">#FF000000</color>
     <color name="examinedProfile">#FFFF5555</color>