diff --git a/xen/common/device_tree.c b/xen/common/device_tree.c
index 4aae281e89..0e8798bd24 100644
--- a/xen/common/device_tree.c
+++ b/xen/common/device_tree.c
@@ -198,7 +198,7 @@ int dt_property_read_string(const struct dt_device_node *np,
 
     if ( !pp )
         return -EINVAL;
-    if ( !pp->value )
+    if ( !pp->length )
         return -ENODATA;
     if ( strnlen(pp->value, pp->length) >= pp->length )
         return -EILSEQ;
diff --git a/xen/include/xen/device_tree.h b/xen/include/xen/device_tree.h
index fd6cd00b43..430a1ef445 100644
--- a/xen/include/xen/device_tree.h
+++ b/xen/include/xen/device_tree.h
@@ -451,6 +451,9 @@ static inline bool_t dt_property_read_bool(const struct dt_device_node *np,
  * doest not have value, and -EILSEQ if the string is not
  * null-terminated with the length of the property data.
  *
+ * Note that the empty string "" has length of 1, thus -ENODATA cannot
+ * be interpreted as an empty string.
+ *
  * The out_string pointer is modified only if a valid string can be decoded.
  */
 int dt_property_read_string(const struct dt_device_node *np,