diff --git a/umaserverdemo/src/main/kotlin/com/lightspark/Vasp1.kt b/umaserverdemo/src/main/kotlin/com/lightspark/Vasp1.kt
index 174d4245..1dd01f10 100644
--- a/umaserverdemo/src/main/kotlin/com/lightspark/Vasp1.kt
+++ b/umaserverdemo/src/main/kotlin/com/lightspark/Vasp1.kt
@@ -141,7 +141,7 @@ class Vasp1(
         }
 
         val lnurlpResponse = try {
-            response.body<LnurlpResponse>()
+            uma.parseAsLnurlpResponse(response.body())
         } catch (e: Exception) {
             call.application.environment.log.error("Failed to parse as UMA lnurlp response, attempting to parse as " +
                 "non-UMA lnurlp response \n${response.bodyAsText()}", e)
@@ -292,7 +292,7 @@ class Vasp1(
 
         val response = httpClient.post(initialRequestData.lnurlpResponse.callback) {
             contentType(ContentType.Application.Json)
-            setBody(payReq)
+            setBody(payReq.toJson())
         }
 
         if (response.status != HttpStatusCode.OK) {
@@ -301,7 +301,7 @@ class Vasp1(
         }
 
         val payReqResponse = try {
-            response.body<PayReqResponse>()
+            uma.parseAsPayReqResponse(response.body())
         } catch (e: Exception) {
             call.respond(HttpStatusCode.InternalServerError, "Failed to parse payreq response.")
             return "Failed to parse payreq response."
diff --git a/umaserverdemo/src/main/kotlin/com/lightspark/Vasp2.kt b/umaserverdemo/src/main/kotlin/com/lightspark/Vasp2.kt
index d1f7ea8d..7954e111 100644
--- a/umaserverdemo/src/main/kotlin/com/lightspark/Vasp2.kt
+++ b/umaserverdemo/src/main/kotlin/com/lightspark/Vasp2.kt
@@ -132,7 +132,7 @@ class Vasp2(
             return "Failed to generate UMA lnurlp response."
         }
 
-        call.respond(response)
+        call.respond(response.toJson())
 
         return "OK"
     }
@@ -188,7 +188,7 @@ class Vasp2(
         }
 
         val request = try {
-            call.receive<PayRequest>()
+            uma.parseAsPayRequest(call.receive<String>())
         } catch (e: Exception) {
             call.respond(HttpStatusCode.BadRequest, "Invalid pay request. ${e.message}")
             return "Invalid pay request."
@@ -236,7 +236,7 @@ class Vasp2(
             return "Failed to create payreq response."
         }
 
-        call.respond(response)
+        call.respond(response.toJson())
 
         return "OK"
     }