diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -3426,7 +3426,9 @@
         return false;
       return !Style.Cpp11BracedListStyle;
     }
-    return false;
+    // Don't attempt to format operator<(), as it is handled later.
+    if (Right.isNot(TT_OverloadedOperatorLParen))
+      return false;
   }
   if (Right.is(tok::ellipsis)) {
     return Left.Tok.isLiteral() || (Left.is(tok::identifier) && Left.Previous &&
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -15472,6 +15472,8 @@
   Space.SpaceBeforeParens = FormatStyle::SBPO_Always;
 
   verifyFormat("int f ();", Space);
+  verifyFormat("bool operator< ();", Space);
+  verifyFormat("bool operator> ();", Space);
   verifyFormat("void f (int a, T b) {\n"
                "  while (true)\n"
                "    continue;\n"