diff --git a/code/espurna/migrate.cpp b/code/espurna/migrate.cpp
index 9e0892c7..984e625f 100644
--- a/code/espurna/migrate.cpp
+++ b/code/espurna/migrate.cpp
@@ -8,18 +8,37 @@ Copyright (C) 2016-2019 by Xose Pérez <xose dot perez at gmail dot com>
 
 #include "settings.h"
 
-void _cmpMoveIndexDown(const char * key, int offset = 0) {
-    if (hasSetting({key, 0})) return;
-    for (unsigned char index = 1; index < SETTINGS_MAX_LIST_COUNT; index++) {
-        const unsigned char prev = index - 1;
-        if (hasSetting({key, index})) {
-            setSetting({key, prev}, getSetting({key, index}).toInt() + offset);
-        } else {
-            delSetting({key, prev});
+#include <vector>
+#include <utility>
+
+namespace {
+
+void delPrefixes(const char** prefixes, size_t size) {
+    std::vector<String> to_purge;
+
+    using namespace settings;
+    kv_store.foreach([&](kvs_type::KeyValueResult&& kv) {
+        auto key = kv.key.read();
+        for (size_t index = 0; index < size; ++index) {
+            if (key.startsWith(prefixes[index])) {
+                to_purge.push_back(std::move(key));
+                return;
+            }
         }
+    });
+
+    for (auto& key : to_purge) {
+        delSetting(key);
     }
 }
 
+template <size_t Size>
+void delPrefixes(const char* (&&prefixes)[Size]) {
+    delPrefixes(prefixes, Size);
+}
+
+} // namespace
+
 // Configuration versions
 //
 // 1: based on Embedis, no board definitions
@@ -44,34 +63,40 @@ void migrate() {
     const auto version = migrateVersion();
     setSetting("cfg", CFG_VERSION);
 
-    if (!version) return;
+    if (!version) {
+        return;
+    }
 
+    // get rid of old keys that were never used until now
+    // and some very old keys that were forced via migrate.ino
     switch (version) {
-        // migrate old version with 1-based indices
-        case 2:
-            _cmpMoveIndexDown("ledGPIO");
-            _cmpMoveIndexDown("ledLogic");
-            _cmpMoveIndexDown("btnGPIO");
-            _cmpMoveIndexDown("btnRelay", -1);
-            _cmpMoveIndexDown("relayGPIO");
-            _cmpMoveIndexDown("relayType");
-            // fall through
-        // get rid / move some existing keys from old migrate.ino
-        case 3:
-            moveSettings("chGPIO", "ltDimmerGPIO");
-            moveSettings("myDIGPIO", "ltMy92DIGPIO");
-            moveSettings("myDCKGPIO", "ltMy92DCKGPIO");
-            moveSettings("myChips", "ltMy92Chips");
-            moveSettings("myModel", "ltMy92Model");
-            moveSettings("chLogic", "ltDimmerInv");
-            moveSettings("ledLogic", "ledInv");
-            delSetting("lightProvider");
-            delSetting("relayProvider");
-            delSetting("relays");
-            delSetting("board");
-            // fall through
-        default:
-            break;
+    case 2:
+        delPrefixes({
+            "btnGPIO",
+            "ledGPIO",
+            "ledLogic",
+            "relayGPIO",
+            "relayType"
+        });
+        // fall through
+    case 3:
+    case 4:
+        delPrefixes({
+            "board",
+            "chGPIO",
+            "chLogic",
+            "ledGPIO",
+            "ledLogic",
+            "lightProvider",
+            "myChips",
+            "myDCKGPIO",
+            "myDIGPIO",
+            "relayGPIO",
+            "relayProvider",
+            "relayType",
+            "relays"
+        });
+        break;
     }
 
     saveSettings();
diff --git a/code/espurna/settings.cpp b/code/espurna/settings.cpp
index f75b68cb..d4cdc69c 100644
--- a/code/espurna/settings.cpp
+++ b/code/espurna/settings.cpp
@@ -335,18 +335,42 @@ String getSetting(const SettingsKey& key, String&& defaultValue) {
     return result.value;
 }
 
+bool delSetting(const String& key) {
+    return settings::kv_store.del(key);
+}
+
 bool delSetting(const SettingsKey& key) {
-    return settings::kv_store.del(key.toString());
+    return delSetting(key.toString());
+}
+
+bool delSetting(const char* key) {
+    return delSetting(String(key));
+}
+
+bool delSetting(const __FlashStringHelper* key) {
+    return delSetting(String(key));
+}
+
+bool hasSetting(const String& key) {
+    return settings::kv_store.has(key);
 }
 
 bool hasSetting(const SettingsKey& key) {
-    return settings::kv_store.has(key.toString());
+    return hasSetting(key.toString());
+}
+
+bool hasSetting(const char* key) {
+    return hasSetting(String(key));
+}
+
+bool hasSetting(const __FlashStringHelper* key) {
+    return hasSetting(String(key));
 }
 
 void saveSettings() {
-    #if not SETTINGS_AUTOSAVE
-        eepromCommit();
-    #endif
+#if not SETTINGS_AUTOSAVE
+    eepromCommit();
+#endif
 }
 
 void resetSettings() {
diff --git a/code/espurna/settings.h b/code/espurna/settings.h
index 51a6d961..b466f33a 100644
--- a/code/espurna/settings.h
+++ b/code/espurna/settings.h
@@ -233,7 +233,14 @@ bool setSetting(const SettingsKey& key, T value) {
     return setSetting(key, std::move(String(value)));
 }
 
+bool delSetting(const char* key);
+bool delSetting(const String& key);
+bool delSetting(const __FlashStringHelper* key);
 bool delSetting(const SettingsKey& key);
+
+bool hasSetting(const char* key);
+bool hasSetting(const String& key);
+bool hasSetting(const __FlashStringHelper* key);
 bool hasSetting(const SettingsKey& key);
 
 void saveSettings();