diff --git a/lightspark-sdk/README.md b/lightspark-sdk/README.md
index 6a6abacb..73a99dd2 100644
--- a/lightspark-sdk/README.md
+++ b/lightspark-sdk/README.md
@@ -17,14 +17,14 @@ Start by installing the SDK from maven:
 **build.gradle:**
 ```groovy
   dependencies {
-    implementation "com.lightspark:lightspark-sdk:0.15.0"
+    implementation "com.lightspark:lightspark-sdk:0.15.1"
   }
 ```
 
 or with **build.gradle.kts:**
 ```kotlin
   dependencies {
-    implementation("com.lightspark:lightspark-sdk:0.15.0")
+    implementation("com.lightspark:lightspark-sdk:0.15.1")
   }
 ```
 
diff --git a/lightspark-sdk/gradle.properties b/lightspark-sdk/gradle.properties
index 34a2d73d..51a47559 100644
--- a/lightspark-sdk/gradle.properties
+++ b/lightspark-sdk/gradle.properties
@@ -1,7 +1,7 @@
 GROUP=com.lightspark
 POM_ARTIFACT_ID=lightspark-sdk
 # Don't bump this manually. Run `scripts/versions.main.kt <new_version>` to bump the version instead.
-VERSION_NAME=0.15.0
+VERSION_NAME=0.15.1
 
 POM_DESCRIPTION=The Lightspark API SDK for Kotlin and Java.
 POM_INCEPTION_YEAR=2023
diff --git a/lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/graphql/PayUmaInvoice.kt b/lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/graphql/PayUmaInvoice.kt
index 972cf45f..22ae6948 100644
--- a/lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/graphql/PayUmaInvoice.kt
+++ b/lightspark-sdk/src/commonMain/kotlin/com/lightspark/sdk/graphql/PayUmaInvoice.kt
@@ -9,7 +9,7 @@ const val PayUmaInvoiceMutation = """
     ${'$'}timeout_secs: Int!
     ${'$'}maximum_fees_msats: Long!
     ${'$'}amount_msats: Long
-    ${'$'}sender_hash: String = null
+    ${'$'}sender_hash: String
   ) {
     pay_uma_invoice(
       input: {