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
@@ -1989,7 +1989,9 @@
     } else if (Current.isOneOf(tok::identifier, tok::kw_const, tok::kw_noexcept,
                                tok::kw_requires) &&
                Current.Previous &&
-               !Current.Previous->isOneOf(tok::equal, tok::at) &&
+               !Current.Previous->isOneOf(tok::equal, tok::at,
+                                          TT_CtorInitializerComma,
+                                          TT_CtorInitializerColon) &&
                Line.MightBeFunctionDecl && Contexts.size() == 1) {
       // Line.MightBeFunctionDecl can only be true after the parentheses of a
       // function declaration have been found.
diff --git a/clang/unittests/Format/TokenAnnotatorTest.cpp b/clang/unittests/Format/TokenAnnotatorTest.cpp
--- a/clang/unittests/Format/TokenAnnotatorTest.cpp
+++ b/clang/unittests/Format/TokenAnnotatorTest.cpp
@@ -1124,6 +1124,35 @@
   EXPECT_TOKEN(Tokens[9], tok::colon, TT_GotoLabelColon);
 }
 
+TEST_F(TokenAnnotatorTest, UnderstandConstructors) {
+  auto Tokens = annotate("Class::Class() : BaseClass(), Member() {}");
+
+  // The TT_Unknown is clearly not binding for the future, please adapt if those
+  // tokens get annotated.
+  ASSERT_EQ(Tokens.size(), 16u) << Tokens;
+  EXPECT_TOKEN(Tokens[5], tok::colon, TT_CtorInitializerColon);
+  EXPECT_TOKEN(Tokens[6], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[7], tok::l_paren, TT_Unknown);
+  EXPECT_TOKEN(Tokens[8], tok::r_paren, TT_Unknown);
+  EXPECT_TOKEN(Tokens[9], tok::comma, TT_CtorInitializerComma);
+  EXPECT_TOKEN(Tokens[10], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[11], tok::l_paren, TT_Unknown);
+  EXPECT_TOKEN(Tokens[12], tok::r_paren, TT_Unknown);
+  EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_FunctionLBrace);
+
+  Tokens = annotate("Class::Class() : BaseClass{}, Member{} {}");
+  ASSERT_EQ(Tokens.size(), 16u) << Tokens;
+  EXPECT_TOKEN(Tokens[5], tok::colon, TT_CtorInitializerColon);
+  EXPECT_TOKEN(Tokens[6], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[7], tok::l_brace, TT_Unknown);
+  EXPECT_TOKEN(Tokens[8], tok::r_brace, TT_Unknown);
+  EXPECT_TOKEN(Tokens[9], tok::comma, TT_CtorInitializerComma);
+  EXPECT_TOKEN(Tokens[10], tok::identifier, TT_Unknown);
+  EXPECT_TOKEN(Tokens[11], tok::l_brace, TT_Unknown);
+  EXPECT_TOKEN(Tokens[12], tok::r_brace, TT_Unknown);
+  EXPECT_TOKEN(Tokens[13], tok::l_brace, TT_FunctionLBrace);
+}
+
 } // namespace
 } // namespace format
 } // namespace clang