diff --git a/docs/release-notes/version-2.11.md b/docs/release-notes/version-2.11.md
index 34c848267..06020a9ac 100644
--- a/docs/release-notes/version-2.11.md
+++ b/docs/release-notes/version-2.11.md
@@ -5,6 +5,7 @@
 ### Bug Fixes
 
 * [#6626](https://github.com/netbox-community/netbox/issues/6626) - Fix site field on VM search form; add site group
+* [#6640](https://github.com/netbox-community/netbox/issues/6640) - Disallow numeric values in custom text fields
 * [#6652](https://github.com/netbox-community/netbox/issues/6652) - Fix exception when adding components in bulk to multiple devices
 
 ---
diff --git a/netbox/extras/models/customfields.py b/netbox/extras/models/customfields.py
index b88c73531..60c6adce9 100644
--- a/netbox/extras/models/customfields.py
+++ b/netbox/extras/models/customfields.py
@@ -280,8 +280,10 @@ class CustomField(BigIDModel):
         if value not in [None, '']:
 
             # Validate text field
-            if self.type == CustomFieldTypeChoices.TYPE_TEXT and self.validation_regex:
-                if not re.match(self.validation_regex, value):
+            if self.type == CustomFieldTypeChoices.TYPE_TEXT:
+                if type(value) is not str:
+                    raise ValidationError(f"Value must be a string.")
+                if self.validation_regex and not re.match(self.validation_regex, value):
                     raise ValidationError(f"Value must match regex '{self.validation_regex}'")
 
             # Validate integer