diff --git a/crates/ruff_linter/resources/test/fixtures/pyflakes/F821_24.py b/crates/ruff_linter/resources/test/fixtures/pyflakes/F821_24.py
new file mode 100644
index 00000000000000..c6356289138ffb
--- /dev/null
+++ b/crates/ruff_linter/resources/test/fixtures/pyflakes/F821_24.py
@@ -0,0 +1,8 @@
+"""Test for accessing class members within a generator."""
+
+
+class Class:
+    items = []
+
+    if len(replacements := {item[1] for item in items}) > 1:
+        pass
diff --git a/crates/ruff_linter/src/checkers/ast/mod.rs b/crates/ruff_linter/src/checkers/ast/mod.rs
index 2cc13787d731b6..d408e49078b518 100644
--- a/crates/ruff_linter/src/checkers/ast/mod.rs
+++ b/crates/ruff_linter/src/checkers/ast/mod.rs
@@ -1748,7 +1748,8 @@ impl<'a> Checker<'a> {
         if self
             .semantic
             .current_expressions()
-            .any(Expr::is_named_expr_expr)
+            .filter_map(Expr::as_named_expr_expr)
+            .any(|parent| parent.target.as_ref() == expr)
         {
             self.add_binding(id, expr.range(), BindingKind::NamedExprAssignment, flags);
             return;
diff --git a/crates/ruff_linter/src/rules/pyflakes/mod.rs b/crates/ruff_linter/src/rules/pyflakes/mod.rs
index 814dcb3d743ecb..721e7dceb72563 100644
--- a/crates/ruff_linter/src/rules/pyflakes/mod.rs
+++ b/crates/ruff_linter/src/rules/pyflakes/mod.rs
@@ -142,6 +142,7 @@ mod tests {
     #[test_case(Rule::UndefinedName, Path::new("F821_21.py"))]
     #[test_case(Rule::UndefinedName, Path::new("F821_22.ipynb"))]
     #[test_case(Rule::UndefinedName, Path::new("F821_23.py"))]
+    #[test_case(Rule::UndefinedName, Path::new("F821_24.py"))]
     #[test_case(Rule::UndefinedExport, Path::new("F822_0.py"))]
     #[test_case(Rule::UndefinedExport, Path::new("F822_1.py"))]
     #[test_case(Rule::UndefinedExport, Path::new("F822_2.py"))]
diff --git a/crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F821_F821_24.py.snap b/crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F821_F821_24.py.snap
new file mode 100644
index 00000000000000..d0b409f39ee0ba
--- /dev/null
+++ b/crates/ruff_linter/src/rules/pyflakes/snapshots/ruff_linter__rules__pyflakes__tests__F821_F821_24.py.snap
@@ -0,0 +1,4 @@
+---
+source: crates/ruff_linter/src/rules/pyflakes/mod.rs
+---
+