diff --git a/internal/service/elasticache/user.go b/internal/service/elasticache/user.go
index 87398d98965..3b374ac7b92 100644
--- a/internal/service/elasticache/user.go
+++ b/internal/service/elasticache/user.go
@@ -90,7 +90,7 @@ func resourceUser() *schema.Resource {
 			names.AttrEngine: {
 				Type:             schema.TypeString,
 				Required:         true,
-				ValidateFunc:     validation.StringInSlice([]string{"REDIS", "VALKEY"}, false),
+				ValidateFunc:     validation.StringInSlice([]string{engineRedis, engineValkey}, true),
 				DiffSuppressFunc: sdkv2.SuppressEquivalentStringCaseInsensitive,
 			},
 			"no_password_required": {
diff --git a/internal/service/elasticache/user_group.go b/internal/service/elasticache/user_group.go
index dc74c76ee64..689d84aa571 100644
--- a/internal/service/elasticache/user_group.go
+++ b/internal/service/elasticache/user_group.go
@@ -50,7 +50,7 @@ func resourceUserGroup() *schema.Resource {
 			names.AttrEngine: {
 				Type:             schema.TypeString,
 				Required:         true,
-				ValidateFunc:     validation.StringInSlice([]string{"REDIS", "VALKEY"}, false),
+				ValidateFunc:     validation.StringInSlice([]string{engineRedis, engineValkey}, true),
 				DiffSuppressFunc: sdkv2.SuppressEquivalentStringCaseInsensitive,
 			},
 			names.AttrTags:    tftags.TagsSchema(),
diff --git a/website/docs/r/elasticache_user.html.markdown b/website/docs/r/elasticache_user.html.markdown
index 96d63d6bd36..eb8455107ea 100644
--- a/website/docs/r/elasticache_user.html.markdown
+++ b/website/docs/r/elasticache_user.html.markdown
@@ -57,7 +57,7 @@ resource "aws_elasticache_user" "test" {
 The following arguments are required:
 
 * `access_string` - (Required) Access permissions string used for this user. See [Specifying Permissions Using an Access String](https://docs.aws.amazon.com/AmazonElastiCache/latest/red-ug/Clusters.RBAC.html#Access-string) for more details.
-* `engine` - (Required) The current supported values are `REDIS`, `VALKEY`.
+* `engine` - (Required) The current supported values are `REDIS`, `VALKEY` (case insensitive).
 * `user_id` - (Required) The ID of the user.
 * `user_name` - (Required) The username of the user.
 
diff --git a/website/docs/r/elasticache_user_group.html.markdown b/website/docs/r/elasticache_user_group.html.markdown
index ca2deb929ba..51f889e8039 100644
--- a/website/docs/r/elasticache_user_group.html.markdown
+++ b/website/docs/r/elasticache_user_group.html.markdown
@@ -32,7 +32,7 @@ resource "aws_elasticache_user_group" "test" {
 
 The following arguments are required:
 
-* `engine` - (Required) The current supported value are `REDIS`, `VALKEY`.
+* `engine` - (Required) The current supported value are `REDIS`, `VALKEY` (case insensitive).
 * `user_group_id` - (Required) The ID of the user group.
 
 The following arguments are optional: