Index: clang/lib/Sema/SemaDeclCXX.cpp
===================================================================
--- clang/lib/Sema/SemaDeclCXX.cpp
+++ clang/lib/Sema/SemaDeclCXX.cpp
@@ -7276,6 +7276,9 @@
     return;
   }
 
+  if (DefKind.isComparison())
+    UnusedPrivateFields.clear();
+
   if (DefKind.isSpecialMember()
           ? CheckExplicitlyDefaultedSpecialMember(cast<CXXMethodDecl>(FD),
                                                   DefKind.asSpecialMember())
Index: clang/test/SemaCXX/warn-unused-private-field.cpp
===================================================================
--- clang/test/SemaCXX/warn-unused-private-field.cpp
+++ clang/test/SemaCXX/warn-unused-private-field.cpp
@@ -1,5 +1,24 @@
 // RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -Wused-but-marked-unused -Wno-uninitialized -verify -std=c++11 %s
 // RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -Wused-but-marked-unused -Wno-uninitialized -verify -std=c++17 %s
+// RUN: %clang_cc1 -fsyntax-only -Wunused-private-field -Wused-but-marked-unused -Wno-uninitialized -verify -std=c++20 %s
+
+#if __cplusplus >= 202002L
+
+class EqDefaultCompare {
+  int unused_;
+
+public:
+  bool operator==(const EqDefaultCompare &) const = default;
+};
+
+class SpaceShipDefaultCompare {
+  int unused_;
+
+public:
+  int operator<=>(const SpaceShipDefaultCompare &) const = default;
+};
+
+#endif
 
 class NotFullyDefined {
  public: