Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -1852,6 +1852,10 @@
     if (Style.Language == FormatStyle::LK_JavaScript)
       return TT_BinaryOperator;
 
+    // && in C# must be a binary operator.
+    if (Style.isCSharp() && Tok.is(tok::ampamp))
+      return TT_BinaryOperator;
+
     const FormatToken *PrevToken = Tok.getPreviousNonComment();
     if (!PrevToken)
       return TT_UnaryOperator;
Index: clang/unittests/Format/FormatTestCSharp.cpp
===================================================================
--- clang/unittests/Format/FormatTestCSharp.cpp
+++ clang/unittests/Format/FormatTestCSharp.cpp
@@ -706,6 +706,9 @@
   verifyFormat(R"(char[,,] rawCharArray = MakeCharacterGrid();)", Style);
   verifyFormat(R"(var (key, value))", Style);
 
+  // `&&` is not seen as a reference.
+  verifyFormat(R"(A == typeof(X) && someBool)", Style);
+
   // Not seen as a C-style cast.
   verifyFormat(R"(//
 foreach ((A a, B b) in someList) {