diff --git a/.changelog/24278.txt b/.changelog/24278.txt
new file mode 100644
index 00000000000..733a7f0ad58
--- /dev/null
+++ b/.changelog/24278.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+resource/aws_elastic_beanstalk_environment: Correctly set `cname_prefix` attribute
+```
\ No newline at end of file
diff --git a/internal/service/elasticbeanstalk/environment.go b/internal/service/elasticbeanstalk/environment.go
index b0ed357acfb..ba801479dde 100644
--- a/internal/service/elasticbeanstalk/environment.go
+++ b/internal/service/elasticbeanstalk/environment.go
@@ -571,7 +571,7 @@ func resourceEnvironmentRead(d *schema.ResourceData, meta interface{}) error {
 	}
 
 	if env.CNAME != nil {
-		beanstalkCnamePrefixRegexp := regexp.MustCompile(`(^[^.]+)(.\w{2}-\w{4,9}-\d)?.(elasticbeanstalk.com|eb.amazonaws.com.cn)$`)
+		beanstalkCnamePrefixRegexp := regexp.MustCompile(`(^[^.]+)(.\w{2}-\w{4,9}-\d)?\.(elasticbeanstalk\.com|eb\.amazonaws\.com\.cn)$`)
 		var cnamePrefix string
 		cnamePrefixMatch := beanstalkCnamePrefixRegexp.FindStringSubmatch(*env.CNAME)