Index: clang/lib/Format/UnwrappedLineParser.cpp
===================================================================
--- clang/lib/Format/UnwrappedLineParser.cpp
+++ clang/lib/Format/UnwrappedLineParser.cpp
@@ -581,7 +581,8 @@
           ProbablyBracedList =
               ProbablyBracedList ||
               (NextTok->is(tok::l_brace) && LBraceStack.back().PrevTok &&
-               LBraceStack.back().PrevTok->is(tok::identifier));
+               LBraceStack.back().PrevTok->isOneOf(tok::identifier,
+                                                   tok::greater));
 
           ProbablyBracedList =
               ProbablyBracedList ||
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -13458,6 +13458,8 @@
   verifyFormat(
       "class A {\n"
       "  A() : a{} {}\n"
+      "  A() : Base<int>{} {}\n"
+      "  A() : Base<Foo<int>>{} {}\n"
       "  A(int b) : b(b) {}\n"
       "  A(int a, int b) : a(a), bs{{bs...}} { f(); }\n"
       "  int a, b;\n"