diff --git a/electrum/gui/qml/components/controls/SeedTextArea.qml b/electrum/gui/qml/components/controls/SeedTextArea.qml
index 9674c008fc2a..38646b5af351 100644
--- a/electrum/gui/qml/components/controls/SeedTextArea.qml
+++ b/electrum/gui/qml/components/controls/SeedTextArea.qml
@@ -16,7 +16,13 @@ Pane {
     property string indicatorText
     property bool indicatorValid
 
+    // Whether to validate individual words against the wordlist.
+    // When true, invalid words are visually flagged (red underline area).
+    // Does not block input - user can still type and correct.
+    property bool validateWords: false
+
     property var _suggestions: []
+    property var _invalidWordIndices: []
 
     onTextChanged: {
         if (seedtextarea.text != text)
@@ -63,6 +69,19 @@ Pane {
                 _suggestions = bitcoin.mnemonicsFor(seedtextarea.text.split(' ').pop())
                 // TODO: cursorPosition only on suggestion apply
                 cursorPosition = text.length
+
+                // per-word validation: flag words not in the wordlist
+                if (root.validateWords) {
+                    var words = seedtextarea.text.split(' ')
+                    // last word may be incomplete (still being typed), skip it
+                    var invalid = []
+                    for (var i = 0; i < words.length - 1; i++) {
+                        if (words[i].length > 0 && !bitcoin.isWordInWordlist(words[i])) {
+                            invalid.push(i)
+                        }
+                    }
+                    _invalidWordIndices = invalid
+                }
             }
 
             Rectangle {
@@ -86,6 +105,19 @@ Pane {
             }
         }
 
+        Label {
+            id: invalidWordWarning
+            visible: root.validateWords && _invalidWordIndices.length > 0
+            text: _invalidWordIndices.length === 1
+                ? qsTr('Word %1 is not in the word list').arg(_invalidWordIndices[0] + 1)
+                : qsTr('%1 words are not in the word list').arg(_invalidWordIndices.length)
+            color: Material.color(Material.Red)
+            font.pixelSize: constants.fontSizeSmall
+            Layout.fillWidth: true
+            wrapMode: Text.Wrap
+            leftPadding: constants.paddingXXSmall
+        }
+
         Flickable {
             Layout.preferredWidth: parent.width
             Layout.minimumHeight: fontMetrics.lineSpacing + 2*constants.paddingXXSmall + 2*constants.paddingXSmall + 2
diff --git a/electrum/gui/qml/components/wizard/WCConfirmSeed.qml b/electrum/gui/qml/components/wizard/WCConfirmSeed.qml
index 5aebaf0b7169..0c1aaa6d67f3 100644
--- a/electrum/gui/qml/components/wizard/WCConfirmSeed.qml
+++ b/electrum/gui/qml/components/wizard/WCConfirmSeed.qml
@@ -45,6 +45,7 @@ WizardComponent {
                 Layout.fillWidth: true
                 Layout.topMargin: constants.paddingSmall
                 placeholderText: qsTr('Enter your seed')
+                validateWords: true
                 onTextChanged: checkValid()
             }
         }
diff --git a/electrum/gui/qml/components/wizard/WCHaveSeed.qml b/electrum/gui/qml/components/wizard/WCHaveSeed.qml
index 95ce6cd6f53c..4bc9fcb9364d 100644
--- a/electrum/gui/qml/components/wizard/WCHaveSeed.qml
+++ b/electrum/gui/qml/components/wizard/WCHaveSeed.qml
@@ -201,6 +201,7 @@ WizardComponent {
                 Layout.topMargin: constants.paddingLarge
 
                 placeholderText: cosigner ? qsTr('Enter cosigner seed') : qsTr('Enter your seed')
+                validateWords: true
 
                 indicatorValid: root._seedValid
                     ? root._seedType == 'bip39' && root._validationMessage
diff --git a/electrum/gui/qml/qebitcoin.py b/electrum/gui/qml/qebitcoin.py
index 2f1f0df409fb..2e150bf93791 100644
--- a/electrum/gui/qml/qebitcoin.py
+++ b/electrum/gui/qml/qebitcoin.py
@@ -125,3 +125,11 @@ def mnemonicsFor(self, fragment):
         if not self._words:
             self._words = set(Mnemonic('en').wordlist).union(set(old_wordlist))
         return sorted(filter(lambda x: x.startswith(fragment), self._words))
+
+    @pyqtSlot(str, result=bool)
+    def isWordInWordlist(self, word):
+        if not word:
+            return True
+        if not self._words:
+            self._words = set(Mnemonic('en').wordlist).union(set(old_wordlist))
+        return word in self._words