diff --git a/src/main/java/org/asamk/signal/commands/GetAttachmentCommand.java b/src/main/java/org/asamk/signal/commands/GetAttachmentCommand.java
index 6deed90a..f2f0450c 100644
--- a/src/main/java/org/asamk/signal/commands/GetAttachmentCommand.java
+++ b/src/main/java/org/asamk/signal/commands/GetAttachmentCommand.java
@@ -40,12 +40,12 @@ public class GetAttachmentCommand implements JsonRpcLocalCommand {
         final var id = ns.getString("id");
 
         try (InputStream attachment = m.retrieveAttachment(id)) {
+            final var bytes = attachment.readAllBytes();
+            final var base64 = Base64.getEncoder().encodeToString(bytes);
             if (outputWriter instanceof PlainTextWriter writer) {
-                final var bytes = attachment.readAllBytes();
-                final var base64 = Base64.getEncoder().encodeToString(bytes);
                 writer.println(base64);
             } else if (outputWriter instanceof JsonWriter writer) {
-                writer.write(new JsonAttachmentData(attachment));
+                writer.write(new JsonAttachmentData(base64));
             }
         } catch (FileNotFoundException ex) {
             throw new UserErrorException("Could not find attachment with ID: " + id, ex);
diff --git a/src/main/java/org/asamk/signal/json/JsonAttachmentData.java b/src/main/java/org/asamk/signal/json/JsonAttachmentData.java
index fd759674..05a90c21 100644
--- a/src/main/java/org/asamk/signal/json/JsonAttachmentData.java
+++ b/src/main/java/org/asamk/signal/json/JsonAttachmentData.java
@@ -1,9 +1,5 @@
 package org.asamk.signal.json;
 
-import com.fasterxml.jackson.databind.annotation.JsonSerialize;
-
-import java.io.InputStream;
-
 public record JsonAttachmentData(
-        @JsonSerialize(using = JsonStreamSerializer.class) InputStream data
+        String data
 ) {}
diff --git a/src/main/java/org/asamk/signal/json/JsonStreamSerializer.java b/src/main/java/org/asamk/signal/json/JsonStreamSerializer.java
deleted file mode 100644
index 4cd2797e..00000000
--- a/src/main/java/org/asamk/signal/json/JsonStreamSerializer.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package org.asamk.signal.json;
-
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.databind.JsonSerializer;
-import com.fasterxml.jackson.databind.SerializerProvider;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-public class JsonStreamSerializer extends JsonSerializer<InputStream> {
-
-    @Override
-    public void serialize(
-            final InputStream value, final JsonGenerator jsonGenerator, final SerializerProvider serializers
-    ) throws IOException {
-        jsonGenerator.writeBinary(value, -1);
-    }
-}