diff --git a/.changes/6f980213-c40e-45ac-aaac-4643830f85a3.json b/.changes/6f980213-c40e-45ac-aaac-4643830f85a3.json
new file mode 100644
index 00000000000..0e684b0071f
--- /dev/null
+++ b/.changes/6f980213-c40e-45ac-aaac-4643830f85a3.json
@@ -0,0 +1,8 @@
+{
+    "id": "6f980213-c40e-45ac-aaac-4643830f85a3",
+    "type": "bugfix",
+    "description": "Bump **smithy-kotlin** to verion **1.5.6** to pick up fixes for chunked stream byte counting",
+    "issues": [
+        "https://github.com/smithy-lang/smithy-kotlin/issues/1285"
+    ]
+}
\ No newline at end of file
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 7ea325116db..34d49c7ce82 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -12,8 +12,8 @@ atomicfu-version = "0.29.0"
 binary-compatibility-validator-version = "0.18.0"
 
 # smithy-kotlin codegen and runtime are versioned separately
-smithy-kotlin-runtime-version = "1.5.4"
-smithy-kotlin-codegen-version = "0.35.4"
+smithy-kotlin-runtime-version = "1.5.6"
+smithy-kotlin-codegen-version = "0.35.6"
 
 # codegen
 smithy-version = "1.60.2"