diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index 360f0c744..06095e621 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -3903,7 +3903,7 @@ bool FieldDef::Deserialize(Parser &parser, const reflection::Field *field) {
   if (IsInteger(value.type.base_type)) {
     value.constant = NumToString(field->default_integer());
   } else if (IsFloat(value.type.base_type)) {
-    value.constant = FloatToString(field->default_real(), 16);
+    value.constant = FloatToString(field->default_real(), 17);
   }
   presence = FieldDef::MakeFieldPresence(field->optional(), field->required());
   padding = field->padding();