diff --git a/.changes/a0f4b35a-028f-4916-9056-9cf69a1b62d1.json b/.changes/a0f4b35a-028f-4916-9056-9cf69a1b62d1.json
new file mode 100644
index 00000000000..2694f4812d8
--- /dev/null
+++ b/.changes/a0f4b35a-028f-4916-9056-9cf69a1b62d1.json
@@ -0,0 +1,5 @@
+{
+    "id": "a0f4b35a-028f-4916-9056-9cf69a1b62d1",
+    "type": "misc",
+    "description": "Upgrade smithy-kotlin to 0.12.4."
+}
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
index d359726afc7..dc6213c38f8 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -12,7 +12,7 @@ sdkVersion=0.17.4-SNAPSHOT
 smithyVersion=1.22.0
 smithyGradleVersion=0.5.3
 # smithy-kotlin codegen and runtime are versioned together
-smithyKotlinVersion=0.12.3-SNAPSHOT
+smithyKotlinVersion=0.12.4
 
 # kotlin
 kotlinVersion=1.7.10
@@ -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