Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -2040,6 +2040,7 @@
   if (Next->MatchingParen->Next &&
       Next->MatchingParen->Next->is(TT_PointerOrReference))
     return true;
+  int TemplateOpenerLevel = 0;
   for (const FormatToken *Tok = Next->Next; Tok && Tok != Next->MatchingParen;
        Tok = Tok->Next) {
     if (Tok->is(tok::l_paren) && Tok->MatchingParen) {
@@ -2049,6 +2050,15 @@
     if (Tok->is(tok::kw_const) || Tok->isSimpleTypeSpecifier() ||
         Tok->isOneOf(TT_PointerOrReference, TT_StartOfName, tok::ellipsis))
       return true;
+    // Keep a track of how deep inside nested templates chevrons we are.
+    if (Tok->is(TT_TemplateOpener))
+      TemplateOpenerLevel++;
+    if (Tok->is(TT_TemplateCloser))
+      TemplateOpenerLevel--;
+    // We need to see a numeric_constant in a template argument e.g. <8>
+    // for it to be an argument that suggests a function decl.
+    if (Tok->is(tok::numeric_constant) && TemplateOpenerLevel > 0)
+      return true;
     if (Tok->isOneOf(tok::l_brace, tok::string_literal, TT_ObjCMethodExpr) ||
         Tok->Tok.isLiteral())
       return false;
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -5419,6 +5419,42 @@
                "}\n"
                "template <class T> T *f(T &c);\n", // No break here.
                Style);
+  verifyFormat("int\n"
+               "foo(A<bool> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
+  verifyFormat("int\n"
+               "foo(A<8> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
+  verifyFormat("int\n"
+               "foo(A<B<bool>, 8> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
+  verifyFormat("int\n"
+               "foo(A<B<8>, bool> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
+  verifyFormat("int\n"
+               "foo(A<B<bool>, bool> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
+  verifyFormat("int\n"
+               "foo(A<B<8>, 8> a)\n"
+               "{\n"
+               "  return a;\n"
+               "}\n",
+               Style);
 }
 
 TEST_F(FormatTest, AlwaysBreakBeforeMultilineStrings) {