Index: include/clang/Basic/DiagnosticLexKinds.td
===================================================================
--- include/clang/Basic/DiagnosticLexKinds.td
+++ include/clang/Basic/DiagnosticLexKinds.td
@@ -471,6 +471,10 @@
 def err_pp_identifier_arg_not_identifier : Error<
   "cannot convert %0 token to an identifier">;
 
+def warn_pp_filename_likely_typo :
+  ExtWarn<"likely typo, expected \"FILENAME\" or <FILENAME> "
+  "but filename is '%0'">, InGroup<UnknownPragmas>;
+
 def warn_pragma_include_alias_mismatch_angle :
    ExtWarn<"angle-bracketed include <%0> cannot be aliased to double-quoted "
    "include \"%1\"">, InGroup<UnknownPragmas>;
Index: lib/Lex/PPDirectives.cpp
===================================================================
--- lib/Lex/PPDirectives.cpp
+++ lib/Lex/PPDirectives.cpp
@@ -1875,9 +1875,16 @@
       }
 
       // If the file is still not found, just go with the vanilla diagnostic
-      if (!File)
-        Diag(FilenameTok, diag::err_pp_file_not_found) << Filename
-                                                       << FilenameRange;
+      if (!File) {
+        // Assuming filename logically starts and end with alphnumeric
+        // character
+        if (!isAlphanumeric(Filename.front()) ||
+            !isAlphanumeric(Filename.back())) {
+          Diag(FilenameTok, diag::warn_pp_filename_likely_typo) << Filename;
+        }
+        Diag(FilenameTok, diag::err_pp_file_not_found)
+            << Filename << FilenameRange;
+      }
     }
   }
 
Index: test/Frontend/include-likely-typo.c
===================================================================
--- /dev/null
+++ test/Frontend/include-likely-typo.c
@@ -0,0 +1,4 @@
+// RUN: not %clang_cc1 -verify -frewrite-includes
+#include "<hello.h>" @expected-warning {{likely typo, expected "FILENAME" or <FILENAME> but filename is '<hello.h>'}}
+@expected-error {{'<hello.h>' file not found}}
+#include " hello.h " @expected-warning {{likely typo, expected "FILENAME" or <FILENAME> but filename is ' hello.h '}}