diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -1325,7 +1325,7 @@
         } else {
           // We found something in this scope, we should not look at the
           // namespace scope
-          SearchNamespaceScope = false;
+          SearchNamespaceScope = Name.getCXXOverloadedOperator() == OO_Equal;
         }
         R.addDecl(ND);
       }
diff --git a/clang/test/SemaCXX/nested-class-assignment-operator-overload.cpp b/clang/test/SemaCXX/nested-class-assignment-operator-overload.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/SemaCXX/nested-class-assignment-operator-overload.cpp
@@ -0,0 +1,18 @@
+/// clang++ incorrectly rejected this program with the following error:
+/// "No matching member function for call to 'operator='"
+///
+/// Refer to github issue 59684
+
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// expected-no-diagnostics
+
+struct Outer {
+  void invokeAssign() { operator=({}); }
+
+  struct Inner {
+    Inner &operator=(int);
+    void invokeAssign(int D) { operator=(D); }
+  };
+};
+
+int main() {}