diff --git a/profiles/forms.py b/profiles/forms.py
index cfccd92fffb8824bafbbef728464cc631d7a4537..5f2f66090b059fe202cc9eb5b64fe8e2e1e416cc 100644
--- a/profiles/forms.py
+++ b/profiles/forms.py
@@ -81,6 +81,21 @@ class ProfileMergeForm(forms.Form):
     to_merge = forms.IntegerField()
     to_merge_into = forms.IntegerField()
 
+    def clean(self):
+        """
+        To merge Profiles, they must be distinct, and it must not be the
+        case that they both are associated to a Contributor instance
+        (which would mean two Contributor objects for the same person).
+        """
+        data = super().clean()
+        if self.cleaned_data['to_merge'] == self.cleaned_data['to_merge_into']:
+            self.add_error(None, 'A Profile cannot be merged into itself.')
+        profile_to_merge = get_object_or_404(Profile, pk=self.cleaned_data['to_merge'])
+        profile_to_merge_into = get_object_or_404(Profile, pk=self.cleaned_data['to_merge_into'])
+        if profile_to_merge.has_contributor and profile_to_merge_into.has_contributor:
+            self.add_error(None, 'Each of these two Profiles has a Contributor. Cannot merge.')
+        return data
+
     def save(self):
         """
         Perform the actual merge: save all data from to-be-deleted profile
diff --git a/profiles/models.py b/profiles/models.py
index 95fefb225f088b0c7ba056db1d745fa8f4c957fa..612a2738fb05f68fe9aa7ddf18633daa42cfb531 100644
--- a/profiles/models.py
+++ b/profiles/models.py
@@ -10,6 +10,7 @@ from scipost.behaviors import orcid_validator
 from scipost.constants import (
     TITLE_CHOICES, SCIPOST_DISCIPLINES, DISCIPLINE_PHYSICS, SCIPOST_SUBJECT_AREAS)
 from scipost.fields import ChoiceArrayField
+from scipost.models import Contributor
 
 from comments.models import Comment
 from journals.models import Publication, PublicationAuthorsTable
@@ -73,6 +74,15 @@ class Profile(models.Model):
     def email(self):
         return getattr(self.emails.filter(primary=True).first(), 'email', '')
 
+    @property
+    def has_contributor(self):
+        has_contributor = False
+        try:
+            has_contributor = (self.contributor is not None)
+        except Contributor.DoesNotExist:
+            pass
+        return has_contributor
+
     def get_absolute_url(self):
         return reverse('profiles:profile_detail', kwargs={'pk': self.id})