diff --git a/gradle.properties b/gradle.properties
index ac39f6cf..3937f1e0 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -99,7 +99,7 @@ ANDROIDX_UI_AUTOMATOR_VERSION=2.2.0-alpha1
 BIP39_VERSION=1.0.2
 COROUTINES_OKHTTP=1.0
 GOOGLE_MATERIAL_VERSION=1.6.0-beta01
-GRPC_VERSION=1.45.1
+GRPC_VERSION=1.46.0
 GSON_VERSION=2.9.0
 GUAVA_VERSION=31.1-android
 JACOCO_VERSION=0.8.8
diff --git a/sdk-lib/build.gradle.kts b/sdk-lib/build.gradle.kts
index b44bfdc5..c66af3b7 100644
--- a/sdk-lib/build.gradle.kts
+++ b/sdk-lib/build.gradle.kts
@@ -204,6 +204,7 @@ dependencies {
     // replaced if needed. For compatibility, we match the library version used in grpc-okhttp:
     // https://github.com/grpc/grpc-java/blob/v1.37.x/build.gradle#L159
     implementation(libs.okio)
+    implementation(libs.okhttp)
 
     // Tests
     testImplementation(libs.kotlin.reflect)
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/SaplingParamTool.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/SaplingParamTool.kt
index 20f6f2e3..ecf5e41e 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/SaplingParamTool.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/SaplingParamTool.kt
@@ -2,10 +2,10 @@ package cash.z.ecc.android.sdk.internal
 
 import cash.z.ecc.android.sdk.exception.TransactionEncoderException
 import cash.z.ecc.android.sdk.ext.ZcashSdk
-import com.squareup.okhttp.OkHttpClient
-import com.squareup.okhttp.Request
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import okhttp3.OkHttpClient
+import okhttp3.Request
 import okio.buffer
 import okio.sink
 import java.io.File
@@ -70,9 +70,13 @@ class SaplingParamTool {
                         file.parentFile?.mkdirsSuspend()
                     }
                     withContext(Dispatchers.IO) {
-                        file.sink().buffer().use {
-                            twig("writing to $file")
-                            it.writeAll(response.body().source())
+                        response.body?.let { body ->
+                            body.source().use { source ->
+                                file.sink().buffer().use { sink ->
+                                    twig("writing to $file")
+                                    sink.writeAll(source)
+                                }
+                            }
                         }
                     }
                 } else {