diff --git a/app/models/formsemestre.py b/app/models/formsemestre.py
index c19e48a2..e985a153 100644
--- a/app/models/formsemestre.py
+++ b/app/models/formsemestre.py
@@ -117,6 +117,7 @@ class FormSemestre(db.Model):
         "ModuleImpl",
         backref="formsemestre",
         lazy="dynamic",
+        cascade="all, delete-orphan",
     )
     etuds = db.relationship(
         "Identite",
diff --git a/app/models/moduleimpls.py b/app/models/moduleimpls.py
index 6bae755b..88c3d0fb 100644
--- a/app/models/moduleimpls.py
+++ b/app/models/moduleimpls.py
@@ -20,14 +20,12 @@ class ModuleImpl(db.Model):
 
     id = db.Column(db.Integer, primary_key=True)
     moduleimpl_id = db.synonym("id")
-    module_id = db.Column(
-        db.Integer,
-        db.ForeignKey("notes_modules.id"),
-    )
+    module_id = db.Column(db.Integer, db.ForeignKey("notes_modules.id"), nullable=False)
     formsemestre_id = db.Column(
         db.Integer,
         db.ForeignKey("notes_formsemestre.id"),
         index=True,
+        nullable=False,
     )
     responsable_id = db.Column("responsable_id", db.Integer, db.ForeignKey("user.id"))
     # formule de calcul moyenne:
diff --git a/app/models/modules.py b/app/models/modules.py
index 77c06274..d4c70c03 100644
--- a/app/models/modules.py
+++ b/app/models/modules.py
@@ -37,7 +37,9 @@ class Module(db.Model):
     # Type: ModuleType.STANDARD, MALUS, RESSOURCE, SAE (enum)
     module_type = db.Column(db.Integer, nullable=False, default=0, server_default="0")
     # Relations:
-    modimpls = db.relationship("ModuleImpl", backref="module", lazy="dynamic")
+    modimpls = db.relationship(
+        "ModuleImpl", backref="module", lazy="dynamic", cascade="all, delete-orphan"
+    )
     ues_apc = db.relationship("UniteEns", secondary="module_ue_coef", viewonly=True)
     tags = db.relationship(
         "NotesTag",
diff --git a/migrations/versions/7e5b519a27e1_cascade_modimpls.py b/migrations/versions/7e5b519a27e1_cascade_modimpls.py
new file mode 100644
index 00000000..42870d01
--- /dev/null
+++ b/migrations/versions/7e5b519a27e1_cascade_modimpls.py
@@ -0,0 +1,43 @@
+"""cascade_modimpls
+
+Revision ID: 7e5b519a27e1
+Revises: 554c13cea377
+Create Date: 2023-01-12 08:49:01.744120
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "7e5b519a27e1"
+down_revision = "554c13cea377"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    #
+    op.execute("DELETE FROM notes_moduleimpl WHERE module_id is NULL;")
+    op.alter_column(
+        "notes_moduleimpl", "module_id", existing_type=sa.INTEGER(), nullable=False
+    )
+    op.execute("DELETE FROM notes_moduleimpl WHERE formsemestre_id is NULL;")
+    op.alter_column(
+        "notes_moduleimpl",
+        "formsemestre_id",
+        existing_type=sa.INTEGER(),
+        nullable=False,
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.alter_column(
+        "notes_moduleimpl", "formsemestre_id", existing_type=sa.INTEGER(), nullable=True
+    )
+    op.alter_column(
+        "notes_moduleimpl", "module_id", existing_type=sa.INTEGER(), nullable=True
+    )
+    # ### end Alembic commands ###
diff --git a/sco_version.py b/sco_version.py
index 0a6f9c9a..96130c74 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.4.25"
+SCOVERSION = "9.4.26"
 
 SCONAME = "ScoDoc"