diff --git a/src/view/form.js b/src/view/form.js
index b8ad4897cf..45e0eaeb99 100644
--- a/src/view/form.js
+++ b/src/view/form.js
@@ -2910,7 +2910,7 @@ function eval_pyson(value){
                 o2m_size = field.get_eval(record).length;
                 size_limit = (((field_size !== undefined) &&
                             (field_size !== null)) &&
-                        (o2m_size >= field_size >= 0));
+                        (o2m_size >= field_size) && (field_size >= 0));
             } else {
                 o2m_size = null;
                 size_limit = false;
@@ -3346,7 +3346,7 @@ function eval_pyson(value){
                 var m2m_size = field.get_eval(record).length;
                 size_limit = (((field_size !== undefined) &&
                             (field_size !== null)) &&
-                        (m2m_size >= field_size >= 0));
+                        (m2m_size >= field_size) && (field_size >= 0));
             }
 
             this.entry.prop('disabled', this._readonly);