diff --git a/.changes/5e48cdf3-de2e-4274-8955-813c2897e3fc.json b/.changes/5e48cdf3-de2e-4274-8955-813c2897e3fc.json
new file mode 100644
index 00000000000..feed3b5f16c
--- /dev/null
+++ b/.changes/5e48cdf3-de2e-4274-8955-813c2897e3fc.json
@@ -0,0 +1,5 @@
+{
+    "id": "5e48cdf3-de2e-4274-8955-813c2897e3fc",
+    "type": "misc",
+    "description": "**Breaking**: Upgrade **smithy-kotlin** version which will replace all instances of `Set<T>` with `List<T>` in service shapes"
+}
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
index 599818a4d6a..0f0f8b21eb9 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -12,7 +12,7 @@ sdkVersion=0.16.8-SNAPSHOT
 smithyVersion=1.22.0
 smithyGradleVersion=0.5.3
 # smithy-kotlin codegen and runtime are versioned together
-smithyKotlinVersion=0.11.2
+smithyKotlinVersion=0.12.0-SNAPSHOT
 
 # kotlin
 kotlinVersion=1.7.0
@@ -39,4 +39,4 @@ slf4jVersion=1.7.36
 
 # dokka config (values specified at build-time as needed)
 smithyKotlinPackageListUrl=
-smithyKotlinDocBaseUrl=https://docs.aws.amazon.com/sdk-for-kotlin/latest/reference/smithy-kotlin
\ No newline at end of file
+smithyKotlinDocBaseUrl=https://docs.aws.amazon.com/sdk-for-kotlin/latest/reference/smithy-kotlin