diff --git a/Lib/fontTools/feaLib/ast.py b/Lib/fontTools/feaLib/ast.py
index 39dc4bcf8..1994fc08c 100644
--- a/Lib/fontTools/feaLib/ast.py
+++ b/Lib/fontTools/feaLib/ast.py
@@ -1143,6 +1143,12 @@ class ValueRecord(Expression):
             elif yAdvance is None and not vertical:
                 return str(xAdvance)
 
+        # Make any remaining None value 0 to avoid generating invalid records.
+        x = x or 0
+        y = y or 0
+        xAdvance = xAdvance or 0
+        yAdvance = yAdvance or 0
+
         # Try format B, if possible.
         if (xPlaDevice is None and yPlaDevice is None and
                 xAdvDevice is None and yAdvDevice is None):
diff --git a/Tests/feaLib/ast_test.py b/Tests/feaLib/ast_test.py
index 7a43d7bf2..54bd5b3e2 100644
--- a/Tests/feaLib/ast_test.py
+++ b/Tests/feaLib/ast_test.py
@@ -11,6 +11,10 @@ class AstTest(unittest.TestCase):
             statement.append(ast.GlyphName(name))
         self.assertEqual(statement.asFea(), r"[\BASE \NULL foo a]")
 
+    def test_valuerecord_none(self):
+        statement = ast.ValueRecord(xPlacement=10, xAdvance=20)
+        self.assertEqual(statement.asFea(), "<10 0 20 0>")
+
 
 if __name__ == "__main__":
     import sys