diff --git a/django/contrib/postgres/fields/array.py b/django/contrib/postgres/fields/array.py
index d2c17438619..ab667acd5bf 100644
--- a/django/contrib/postgres/fields/array.py
+++ b/django/contrib/postgres/fields/array.py
@@ -19,7 +19,7 @@ __all__ = ['ArrayField']
 class ArrayField(CheckFieldDefaultMixin, Field):
     empty_strings_allowed = False
     default_error_messages = {
-        'item_invalid': _('Item %(nth)s in the array did not validate: '),
+        'item_invalid': _('Item %(nth)s in the array did not validate:'),
         'nested_array_mismatch': _('Nested arrays must have the same length.'),
     }
     _default_hint = ('list', '[]')
diff --git a/django/contrib/postgres/forms/array.py b/django/contrib/postgres/forms/array.py
index 6c18a37ebf6..554a39d4f6b 100644
--- a/django/contrib/postgres/forms/array.py
+++ b/django/contrib/postgres/forms/array.py
@@ -13,7 +13,7 @@ from ..utils import prefix_validation_error
 
 class SimpleArrayField(forms.CharField):
     default_error_messages = {
-        'item_invalid': _('Item %(nth)s in the array did not validate: '),
+        'item_invalid': _('Item %(nth)s in the array did not validate:'),
     }
 
     def __init__(self, base_field, *, delimiter=',', max_length=None, min_length=None, **kwargs):
@@ -167,7 +167,7 @@ class SplitArrayWidget(forms.Widget):
 
 class SplitArrayField(forms.Field):
     default_error_messages = {
-        'item_invalid': _('Item %(nth)s in the array did not validate: '),
+        'item_invalid': _('Item %(nth)s in the array did not validate:'),
     }
 
     def __init__(self, base_field, size, *, remove_trailing_nulls=False, **kwargs):
diff --git a/django/contrib/postgres/utils.py b/django/contrib/postgres/utils.py
index 9f92f4059f4..f3c022f4740 100644
--- a/django/contrib/postgres/utils.py
+++ b/django/contrib/postgres/utils.py
@@ -17,7 +17,7 @@ def prefix_validation_error(error, prefix, code, params):
             # ngettext calls require a count parameter and are converted
             # to an empty string if they are missing it.
             message=format_lazy(
-                '{}{}',
+                '{} {}',
                 SimpleLazyObject(lambda: prefix % params),
                 SimpleLazyObject(lambda: error.message % error_params),
             ),