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
@@ -2153,7 +2153,7 @@
       // before the parentheses, this is unlikely to be a cast.
       if (LeftOfParens->Tok.getIdentifierInfo() &&
           !LeftOfParens->isOneOf(Keywords.kw_in, tok::kw_return, tok::kw_case,
-                                 tok::kw_delete)) {
+                                 tok::kw_delete, tok::kw_throw)) {
         return false;
       }
 
@@ -3312,6 +3312,10 @@
       !Right.isOneOf(tok::semi, tok::r_paren, tok::hashhash)) {
     return true;
   }
+  if (Left.is(tok::kw_throw) && Right.is(tok::l_paren) && Right.MatchingParen &&
+      Right.MatchingParen->is(TT_CastRParen)) {
+    return true;
+  }
   if (Style.isJson() && Left.is(tok::string_literal) && Right.is(tok::colon))
     return false;
   if (Left.is(Keywords.kw_assert) && Style.Language == FormatStyle::LK_Java)
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
@@ -10958,6 +10958,7 @@
   verifyFormat("my_int a = (my_int)2.0f;");
   verifyFormat("my_int a = (my_int)sizeof(int);");
   verifyFormat("return (my_int)aaa;");
+  verifyFormat("throw (my_int)aaa;");
   verifyFormat("#define x ((int)-1)");
   verifyFormat("#define LENGTH(x, y) (x) - (y) + 1");
   verifyFormat("#define p(q) ((int *)&q)");