diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index 2930d6a..9b0bc70 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -322,7 +322,7 @@
     // using reinterpret_cast.
     UTF16 *ResultPtr = reinterpret_cast<UTF16*>(ResultBuf);
 
-    if (UcnVal < (UTF32)0xFFFF) {
+    if (UcnVal <= (UTF32)0xFFFF) {
       *ResultPtr = UcnVal;
       ResultBuf += 2;
       return;
diff --git a/test/Lexer/char-literal.cpp b/test/Lexer/char-literal.cpp
index 5dc5360..8556d46 100644
--- a/test/Lexer/char-literal.cpp
+++ b/test/Lexer/char-literal.cpp
@@ -22,3 +22,6 @@
 
 char32_t n = U'ab'; // expected-error {{Unicode character literals may not contain multiple characters}}
 char16_t o = '👽'; // expected-error {{character too large for enclosing character literal type}}
+
+char16_t p[2] = u"\U0000FFFF";
+char16_t q[2] = u"\U00010000"; // expected-error {{too long}}