diff --git a/tests/cypress/e2e/public_programs/programs_page.cy.js b/tests/cypress/e2e/public_programs/programs_page.cy.js
index ba53635d5d1..10461f94fd4 100644
--- a/tests/cypress/e2e/public_programs/programs_page.cy.js
+++ b/tests/cypress/e2e/public_programs/programs_page.cy.js
@@ -9,7 +9,7 @@ describe("General tests for my programs page (with both custom teacher and built
     const adventure = 'story'
     beforeEach(() => {
         loginForTeacher();
-    }) 
+    })
 
     it("create adventure, run its code, and see it in my programs", () => {
         createAdventure(programName);
@@ -31,7 +31,7 @@ describe("General tests for my programs page (with both custom teacher and built
         // make sure to navigate to the wanted program tab.
         cy.get(`[data-cy="${adventure}"]`)
             .click();
-        // Paste example code 
+        // Paste example code
         cy.get(`[data-cy="paste-example-code-${adventure}"]`).click();
         cy.get('#runit').click();
         cy.wait(500);
diff --git a/tests/cypress/e2e/tools/profile/profile.js b/tests/cypress/e2e/tools/profile/profile.js
index ad08b6afe27..9fff3b0d5cf 100644
--- a/tests/cypress/e2e/tools/profile/profile.js
+++ b/tests/cypress/e2e/tools/profile/profile.js
@@ -4,6 +4,6 @@ export function makeProfilePublic() {
     goToProfilePage();
     cy.get('#public_profile_button').click();
     cy.get('#personal_text').type('updating profile to be public');
-    cy.get('#agree_terms').click();
+    cy.get('#agree_terms').check();  // May start out checked, in which case 'click()' would undo the check!
     cy.get('#submit_public_profile').click();
 }
\ No newline at end of file
diff --git a/website/database.py b/website/database.py
index 4281be9bac7..4339dadc04e 100644
--- a/website/database.py
+++ b/website/database.py
@@ -899,8 +899,7 @@ def set_favourite_program(self, username, program_id, set_favourite):
         # We can only set a favourite program is there is already a public profile
         data = PUBLIC_PROFILES.get({"username": username})
         if data:
-            data["favourite_program"] = program_id if set_favourite else ''
-            self.update_public_profile(username, data)
+            self.update_public_profile(username, {"favourite_program": program_id if set_favourite else ''})
             return True
         return False
 
diff --git a/website/dynamo.py b/website/dynamo.py
index 3452b603418..09c971e1b7f 100644
--- a/website/dynamo.py
+++ b/website/dynamo.py
@@ -369,6 +369,13 @@ def update(self, key, updates):
         self._validate_indexable_fields(updates, True)
         self._validate_key(key)
 
+        updating_keys = set(updates.keys()) & set(self.key_schema.key_names)
+        if updating_keys:
+            raise RuntimeError(' '.join([
+                'update() may not include a key field in the \'updates\' field',
+                f'({updating_keys} may not be part of {updates};',
+                'did you accidentally pass an entire record to update()?)']))
+
         return self.storage.update(self.table_name, key, updates)
 
     @querylog.timed_as("db_del")
diff --git a/website/programs.py b/website/programs.py
index ecdb46ddb76..c0a70cac11a 100644
--- a/website/programs.py
+++ b/website/programs.py
@@ -77,6 +77,7 @@ def store_user_program(self,
             updates['public'] = 1 if set_public else 0
 
         if program_id:
+            # Updates an existing program
             # FIXME: This should turn into a conditional update
             current_prog = self.db.program_by_id(program_id)
             if not current_prog:
@@ -86,6 +87,7 @@ def store_user_program(self,
 
             program = self.db.update_program(program_id, updates)
         else:
+            # Creates a new program
             updates['id'] = uuid.uuid4().hex
             program = self.db.store_program(updates)
 
@@ -101,8 +103,7 @@ def store_user_program(self,
         # and if it was already modified and now is so again, count should not increase.
         if is_modified and not program.get('is_modified'):
             self.db.increase_user_program_count(user["username"])
-        program['is_modified'] = is_modified
-        program = self.db.update_program(program['id'], program)
+            program = self.db.update_program(program['id'], {'is_modified': True})
 
         querylog.log_value(program_id=program['id'],
                            adventure_name=adventure_name, error=error, code_lines=len(code.split('\n')))