diff --git a/llvm/lib/Support/YAMLParser.cpp b/llvm/lib/Support/YAMLParser.cpp
index c66c755c6ec1..8526d9adae36 100644
--- a/llvm/lib/Support/YAMLParser.cpp
+++ b/llvm/lib/Support/YAMLParser.cpp
@@ -1732,8 +1732,10 @@ StringRef ScalarNode::unescapeDoubleQuoted( StringRef UnquotedValue
           if (UnquotedValue.size() < 3)
             // TODO: Report error.
             break;
-          unsigned int UnicodeScalarValue = 0;
-          UnquotedValue.substr(1, 2).getAsInteger(16, UnicodeScalarValue);
+          unsigned int UnicodeScalarValue;
+          if (UnquotedValue.substr(1, 2).getAsInteger(16, UnicodeScalarValue))
+            // TODO: Report error.
+            UnicodeScalarValue = 0xFFFD;
           encodeUTF8(UnicodeScalarValue, Storage);
           UnquotedValue = UnquotedValue.substr(2);
           break;
@@ -1742,8 +1744,10 @@ StringRef ScalarNode::unescapeDoubleQuoted( StringRef UnquotedValue
           if (UnquotedValue.size() < 5)
             // TODO: Report error.
             break;
-          unsigned int UnicodeScalarValue = 0;
-          UnquotedValue.substr(1, 4).getAsInteger(16, UnicodeScalarValue);
+          unsigned int UnicodeScalarValue;
+          if (UnquotedValue.substr(1, 4).getAsInteger(16, UnicodeScalarValue))
+            // TODO: Report error.
+            UnicodeScalarValue = 0xFFFD;
           encodeUTF8(UnicodeScalarValue, Storage);
           UnquotedValue = UnquotedValue.substr(4);
           break;
@@ -1752,8 +1756,10 @@ StringRef ScalarNode::unescapeDoubleQuoted( StringRef UnquotedValue
           if (UnquotedValue.size() < 9)
             // TODO: Report error.
             break;
-          unsigned int UnicodeScalarValue = 0;
-          UnquotedValue.substr(1, 8).getAsInteger(16, UnicodeScalarValue);
+          unsigned int UnicodeScalarValue;
+          if (UnquotedValue.substr(1, 8).getAsInteger(16, UnicodeScalarValue))
+            // TODO: Report error.
+            UnicodeScalarValue = 0xFFFD;
           encodeUTF8(UnicodeScalarValue, Storage);
           UnquotedValue = UnquotedValue.substr(8);
           break;