diff --git a/src/inline_snapshot/_adapter/value_adapter.py b/src/inline_snapshot/_adapter/value_adapter.py
index f44d2358..ce58c4a8 100644
--- a/src/inline_snapshot/_adapter/value_adapter.py
+++ b/src/inline_snapshot/_adapter/value_adapter.py
@@ -1,9 +1,13 @@
 from __future__ import annotations
 
+import ast
+import warnings
+
 from inline_snapshot._code_repr import value_code_repr
 from inline_snapshot._unmanaged import Unmanaged
 from inline_snapshot._unmanaged import update_allowed
 from inline_snapshot._utils import value_to_token
+from inline_snapshot.syntax_warnings import InlineSnapshotInfo
 
 from .._change import Replace
 from .adapter import Adapter
@@ -31,6 +35,16 @@ def assign(self, old_value, old_node, new_value):
         else:
             new_token = value_to_token(new_value)
 
+        if isinstance(old_node, ast.JoinedStr):
+            if not old_value == new_value:
+                warnings.warn_explicit(
+                    f"inline-snapshot will be able to fix f-strings in the future.\nThe current string value is:\n   {new_value!r}",
+                    filename=self.context._source.filename,
+                    lineno=old_node.lineno,
+                    category=InlineSnapshotInfo,
+                )
+            return old_value
+
         if not old_value == new_value:
             flag = "fix"
         elif (
diff --git a/src/inline_snapshot/_inline_snapshot.py b/src/inline_snapshot/_inline_snapshot.py
index 62dcfcf0..a8741fdf 100644
--- a/src/inline_snapshot/_inline_snapshot.py
+++ b/src/inline_snapshot/_inline_snapshot.py
@@ -33,10 +33,6 @@
 from ._utils import value_to_token
 
 
-class NotImplementedYet(Exception):
-    pass
-
-
 snapshots = {}  # type: Dict[Tuple[int, int], SnapshotReference]
 
 _active = False
@@ -54,10 +50,6 @@ def _return(result):
     return result
 
 
-class InlineSnapshotSyntaxWarning(Warning):
-    pass
-
-
 class Flags:
     """
     fix: the value needs to be changed to pass the tests
@@ -140,10 +132,10 @@ def _visible_value(self):
             return self._old_value
 
     def _get_changes(self) -> Iterator[Change]:
-        raise NotImplementedYet()
+        raise NotImplementedError()
 
     def _new_code(self):
-        raise NotImplementedYet()
+        raise NotImplementedError()
 
     def __repr__(self):
         return repr(self._visible_value())
diff --git a/src/inline_snapshot/syntax_warnings.py b/src/inline_snapshot/syntax_warnings.py
index 35dc21a0..a403ec16 100644
--- a/src/inline_snapshot/syntax_warnings.py
+++ b/src/inline_snapshot/syntax_warnings.py
@@ -1,2 +1,6 @@
 class InlineSnapshotSyntaxWarning(Warning):
     pass
+
+
+class InlineSnapshotInfo(Warning):
+    pass