diff --git a/src/internal/kms.ts b/src/internal/kms.ts
index c56ace1..175b6ae 100644
--- a/src/internal/kms.ts
+++ b/src/internal/kms.ts
@@ -29,6 +29,7 @@ export class KMSClient extends AWSClient {
             credentials: {
                 accessKeyId: awsConfig.accessKeyId,
                 secretAccessKey: awsConfig.secretAccessKey,
+                sessionToken: awsConfig.sessionToken,
             },
             uriEscapePath: true,
             applyChecksum: false,
diff --git a/src/internal/ssm.ts b/src/internal/ssm.ts
index a79a939..b9e8aeb 100644
--- a/src/internal/ssm.ts
+++ b/src/internal/ssm.ts
@@ -36,6 +36,7 @@ export class SystemsManagerClient extends AWSClient {
             credentials: {
                 accessKeyId: awsConfig.accessKeyId,
                 secretAccessKey: awsConfig.secretAccessKey,
+                sessionToken: awsConfig.sessionToken,
             },
             uriEscapePath: true,
             applyChecksum: false,