diff --git a/reflection.json b/reflection.json
index 23a62826..26f91f9b 100644
--- a/reflection.json
+++ b/reflection.json
@@ -413,6 +413,11 @@
   "allPublicMethods" : true,
   "allPublicFields" : true,
   "allPublicConstructors" : true
+}, {
+  "name" : "sun.net.www.http.PosterOutputStream",
+  "allPublicMethods" : true,
+  "allPublicFields" : true,
+  "allPublicConstructors" : true
 }, {
   "name" : "sun.net.www.protocol.http.HttpURLConnection",
   "allPublicMethods" : true,
diff --git a/src/babashka/impl/classes.clj b/src/babashka/impl/classes.clj
index 2b9726cc..c276ee85 100644
--- a/src/babashka/impl/classes.clj
+++ b/src/babashka/impl/classes.clj
@@ -91,6 +91,7 @@
                       sun.net.www.protocol.https.HttpsURLConnectionImpl ;; needed fo clj-http.lite
                       sun.net.www.protocol.http.HttpURLConnection ;; needed for clj.http.lite http calls
                       sun.net.www.protocol.http.HttpURLConnection$HttpInputStream ;; needed for clj-http.lite
+                      sun.net.www.http.PosterOutputStream ;; needed for clj-http.lite
                       ]
    :custom-classes {'java.lang.Thread
                     {:allPublicConstructors true