diff --git a/gradle.properties b/gradle.properties
index 83a385f4d5f..44015c8ccb2 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,7 +6,7 @@ kotlin.native.ignoreDisabledTargets=true
 org.gradle.jvmargs=-Xmx6g -XX:MaxMetaspaceSize=2G
 
 # sdk
-sdkVersion=1.3.8
+sdkVersion=1.3.9-SNAPSHOT
 
 # dokka config (values specified at build-time as needed)
 smithyKotlinDocBaseUrl=https://sdk.amazonaws.com/kotlin/api/smithy-kotlin/api/$smithyKotlinRuntimeVersion/