diff --git a/alembic/versions/341068089f14_add_preserve_on_migration_to_block.py b/alembic/versions/341068089f14_add_preserve_on_migration_to_block.py
index aba81f47..c36d9b00 100644
--- a/alembic/versions/341068089f14_add_preserve_on_migration_to_block.py
+++ b/alembic/versions/341068089f14_add_preserve_on_migration_to_block.py
@@ -21,7 +21,7 @@ depends_on: Union[str, Sequence[str], None] = None
 
 def upgrade() -> None:
     # ### commands auto generated by Alembic - please adjust! ###
-    op.add_column("block", sa.Column("preserve_on_migration", sa.Boolean(), nullable=False))
+    op.add_column("block", sa.Column("preserve_on_migration", sa.Boolean(), nullable=True))
     # ### end Alembic commands ###
 
 
diff --git a/letta/orm/block.py b/letta/orm/block.py
index ae895763..994a04c4 100644
--- a/letta/orm/block.py
+++ b/letta/orm/block.py
@@ -35,7 +35,7 @@ class Block(OrganizationMixin, SqlalchemyBase):
     is_template: Mapped[bool] = mapped_column(
         doc="whether the block is a template (e.g. saved human/persona options as baselines for other templates)", default=False
     )
-    preserve_on_migration: Mapped[bool] = mapped_column(doc="preserve the block on template migration", default=False)
+    preserve_on_migration: Mapped[Optional[bool]] = mapped_column(doc="preserve the block on template migration", default=False)
     value: Mapped[str] = mapped_column(doc="Text content of the block for the respective section of core memory.")
     limit: Mapped[BigInteger] = mapped_column(Integer, default=CORE_MEMORY_BLOCK_CHAR_LIMIT, doc="Character limit of the block.")
     metadata_: Mapped[Optional[dict]] = mapped_column(JSON, default={}, doc="arbitrary information related to the block.")
diff --git a/letta/schemas/block.py b/letta/schemas/block.py
index 8d3da3b9..8b00d5c1 100644
--- a/letta/schemas/block.py
+++ b/letta/schemas/block.py
@@ -21,7 +21,7 @@ class BaseBlock(LettaBase, validate_assignment=True):
     # template data (optional)
     template_name: Optional[str] = Field(None, description="Name of the block if it is a template.", alias="name")
     is_template: bool = Field(False, description="Whether the block is a template (e.g. saved human/persona options).")
-    preserve_on_migration: bool = Field(False, description="Preserve the block on template migration.")
+    preserve_on_migration: Optional[bool] = Field(False, description="Preserve the block on template migration.")
 
     # context window label
     label: Optional[str] = Field(None, description="Label of the block (e.g. 'human', 'persona') in the context window.")