diff --git a/snowcap/lifecycle.py b/snowcap/lifecycle.py
index 701f4f5..05545af 100644
--- a/snowcap/lifecycle.py
+++ b/snowcap/lifecycle.py
@@ -6,7 +6,7 @@
 from .builder import tidy_sql
 from .enums import GrantType, ResourceType
 from .identifiers import FQN, URN
-from .props import BoolProp, IntProp, Props, StringProp
+from .props import BoolProp, IntProp, Props, StringProp, quote_value
 from .resource_name import ResourceName
 
 __this__ = sys.modules[__name__]
@@ -508,9 +508,9 @@ def update_scanner_package(urn: URN, data: dict, props: Props) -> str:
     package_name = f"'{urn.fqn.name}'"
     attr, new_value = data.popitem()
     if attr == "schedule":
-        new_value = f"'USING CRON {new_value}'"
+        new_value = quote_value(f"USING CRON {new_value}")
     else:
-        new_value = f"'{new_value}'"
+        new_value = quote_value(new_value)
     return tidy_sql(
         "CALL SNOWFLAKE.TRUST_CENTER.SET_CONFIGURATION(",
         f"'{attr}',",
@@ -535,7 +535,7 @@ def update_schema(urn: URN, data: dict, props: Props) -> str:
     elif attr == "managed_access":
         return tidy_sql("ALTER SCHEMA", urn.fqn, "ENABLE" if new_value else "DISABLE", "MANAGED ACCESS")
     else:
-        new_value = f"'{new_value}'" if isinstance(new_value, str) else new_value
+        new_value = quote_value(new_value) if isinstance(new_value, str) else new_value
         return tidy_sql("ALTER SCHEMA", urn.fqn, "SET", attr, "=", new_value)
 
 
diff --git a/snowcap/props.py b/snowcap/props.py
index d478bf1..acab577 100644
--- a/snowcap/props.py
+++ b/snowcap/props.py
@@ -27,6 +27,10 @@
 def quote_value(value: str):
     if value is None or value == "":
         return "''"
+    if "$$" in str(value):
+        # JSON and Snowflake share backslash escape syntax for control characters
+        escaped = json.dumps(str(value), ensure_ascii=False)[1:-1].replace("'", "''")
+        return f"'{escaped}'"
     return f"$${value}$$"
 
 
diff --git a/tests/test_lifecycle.py b/tests/test_lifecycle.py
index 1d08006..eda88e3 100644
--- a/tests/test_lifecycle.py
+++ b/tests/test_lifecycle.py
@@ -874,7 +874,15 @@ def test_update_other_property(self):
         props = MockProps("")
         result = update_scanner_package(urn, data, props)
         assert "'enabled'" in result
-        assert "'TRUE'" in result
+        assert "$$TRUE$$" in result
+
+    def test_update_comment_with_apostrophe(self):
+        """A value containing an apostrophe must not break out of the literal."""
+        urn = make_urn(ResourceType.SCANNER_PACKAGE, "CIS_BENCHMARKS")
+        data = {"comment": "the account's weekly scan"}
+        props = MockProps("")
+        result = update_scanner_package(urn, data, props)
+        assert "$$the account's weekly scan$$" in result
 
 
 class TestUpdateSchema:
@@ -937,6 +945,22 @@ def test_set_other_property(self):
         result = update_schema(urn, data, props)
         assert "SET data_retention_time_in_days = 7" in result
 
+    def test_set_comment_with_apostrophe(self):
+        """A comment containing an apostrophe must not break out of the literal."""
+        urn = make_urn(ResourceType.SCHEMA, "MY_SCHEMA", database="MY_DB")
+        data = {"comment": "the database's two-limb test"}
+        props = MockProps("")
+        result = update_schema(urn, data, props)
+        assert result == "ALTER SCHEMA MY_DB.MY_SCHEMA SET comment = $$the database's two-limb test$$"
+
+    def test_set_comment_containing_dollar_quote(self):
+        """A comment containing $$ falls back to a single-quoted literal."""
+        urn = make_urn(ResourceType.SCHEMA, "MY_SCHEMA", database="MY_DB")
+        data = {"comment": "costs $$ and it's dear"}
+        props = MockProps("")
+        result = update_schema(urn, data, props)
+        assert result == "ALTER SCHEMA MY_DB.MY_SCHEMA SET comment = 'costs $$ and it''s dear'"
+
 
 class TestUpdateTable:
     """Tests for update_table function."""
diff --git a/tests/test_props.py b/tests/test_props.py
index e31ca48..9c77b56 100644
--- a/tests/test_props.py
+++ b/tests/test_props.py
@@ -124,28 +124,26 @@ def test_props_render(self):
 # ============================================================================
 
 
-class TestQuoteValue:
-    """Tests for the quote_value helper function."""
-
-    def test_quote_value_normal_string(self):
-        result = quote_value("hello world")
-        assert result == "$$hello world$$"
-
-    def test_quote_value_empty_string(self):
-        result = quote_value("")
-        assert result == "''"
-
-    def test_quote_value_none(self):
-        result = quote_value(None)
-        assert result == "''"
-
-    def test_quote_value_with_quotes(self):
-        result = quote_value('it\'s a "test"')
-        assert result == '$$it\'s a "test"$$'
-
-    def test_quote_value_multiline(self):
-        result = quote_value("line1\nline2")
-        assert result == "$$line1\nline2$$"
+@pytest.mark.parametrize(
+    "value, expected",
+    [
+        ("hello world", "$$hello world$$"),
+        ("", "''"),
+        (None, "''"),
+        ('it\'s a "test"', '$$it\'s a "test"$$'),
+        ("line1\nline2", "$$line1\nline2$$"),
+        # $$ in the value forces the single-quoted fallback
+        ("costs $$ and it's dear", "'costs $$ and it''s dear'"),
+        ('$$ say "hi"', "'$$ say \\\"hi\\\"'"),
+        ("$$ path C:\\tmp", "'$$ path C:\\\\tmp'"),
+        ("costs $$\nper line", "'costs $$\\nper line'"),
+        ("$$\r\tx", "'$$\\r\\tx'"),
+        ("$$\b\fx", "'$$\\b\\fx'"),
+        ("$$\0x", "'$$\\u0000x'"),
+    ],
+)
+def test_quote_value(value, expected):
+    assert quote_value(value) == expected
 
 
 class TestBoolPropExtended: