diff --git a/CHANGELOG.md b/CHANGELOG.md
index 24ffa7855..6710e2aae 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ BUG FIXES:
   * providers/aws: Drain autoscale groups before deleting. [GH-435]
   * providers/aws: Fix crash case if launch config is manually deleted. [GH-421]
   * providers/aws: Disassociate EIP before destroying.
+  * providers/aws: ELB treats subnets as a set.
 
 ## 0.3.0 (October 14, 2014)
 
diff --git a/builtin/providers/aws/resource_aws_elb.go b/builtin/providers/aws/resource_aws_elb.go
index 9fffd321e..7782f7d45 100644
--- a/builtin/providers/aws/resource_aws_elb.go
+++ b/builtin/providers/aws/resource_aws_elb.go
@@ -59,11 +59,14 @@ func resourceAwsElb() *schema.Resource {
 
 			// TODO: could be not ForceNew
 			"subnets": &schema.Schema{
-				Type:     schema.TypeList,
+				Type:     schema.TypeSet,
 				Elem:     &schema.Schema{Type: schema.TypeString},
 				Optional: true,
 				ForceNew: true,
 				Computed: true,
+				Set: func(v interface{}) int {
+					return hashcode.String(v.(string))
+				},
 			},
 
 			// TODO: could be not ForceNew