diff --git a/wagtail/wagtailadmin/forms.py b/wagtail/wagtailadmin/forms.py
index 148e83e1bc..3f02b42858 100644
--- a/wagtail/wagtailadmin/forms.py
+++ b/wagtail/wagtailadmin/forms.py
@@ -46,7 +46,9 @@ class PasswordResetForm(PasswordResetForm):
 
         # Find users of this email address
         UserModel = get_user_model()
-        email = cleaned_data['email']
+        email = cleaned_data.get('email')
+        if not email:
+            raise forms.ValidationError("Please fill your email address.")
         active_users = UserModel._default_manager.filter(email__iexact=email, is_active=True)
 
         if active_users.exists():
diff --git a/wagtail/wagtailadmin/templates/wagtailadmin/account/password_reset/form.html b/wagtail/wagtailadmin/templates/wagtailadmin/account/password_reset/form.html
index d36f1b1561..2795f130e6 100644
--- a/wagtail/wagtailadmin/templates/wagtailadmin/account/password_reset/form.html
+++ b/wagtail/wagtailadmin/templates/wagtailadmin/account/password_reset/form.html
@@ -15,8 +15,6 @@
             {% csrf_token %}
             <h1>Reset your password</h1>
 
-            <p>Enter your email address in the box below</p>
-
             {% if form.non_field_errors %}
                 <div class="messages">
                     <ul>
@@ -28,6 +26,7 @@
             {% endif %}
 
             <ul class="fields">
+                <li>Enter your email address in the box below</li>
                 <li>
                     <div class="field">
                         {{ form.email.label_tag }}