diff --git a/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEAccountService.java b/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEAccountService.java
index b4d43fcf567..38db0b2c3dc 100644
--- a/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEAccountService.java
+++ b/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEAccountService.java
@@ -17,6 +17,8 @@
 import javax.ws.rs.core.Response.ResponseBuilder;
 import javax.ws.rs.core.UriInfo;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+
 import org.dogtagpki.acme.ACMEAccount;
 import org.dogtagpki.acme.ACMEHeader;
 import org.dogtagpki.acme.ACMENonce;
@@ -74,7 +76,12 @@ public Response updateAccount(@PathParam("id") String accountID, JWS jws) throws
         String payload = new String(jws.getPayloadAsBytes(), "UTF-8");
         logger.info("Payload: " + payload);
 
-        ACMEAccount update = ACMEAccount.fromJSON(payload);
+        ACMEAccount update;
+        try {
+            update = ACMEAccount.fromJSON(payload);
+        } catch (JsonProcessingException e) {
+            throw engine.createMalformedException(e.toString());
+        }
 
         String newStatus = update.getStatus();
         if (newStatus != null) {
diff --git a/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEEngine.java b/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEEngine.java
index 938c9b76f47..92a8baa99a5 100644
--- a/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEEngine.java
+++ b/base/acme/src/main/java/org/dogtagpki/acme/server/ACMEEngine.java
@@ -728,6 +728,18 @@ public Exception createAccountDoesNotExistException(String accountID) {
         return new WebApplicationException(builder.build());
     }
 
+    public Exception createMalformedException(String desc) {
+        ResponseBuilder builder = Response.status(Response.Status.BAD_REQUEST);
+        builder.type("application/problem+json");
+
+        ACMEError error = new ACMEError();
+        error.setType("urn:ietf:params:acme:error:malformed");
+        error.setDetail("Malformed request: " + desc);
+        builder.entity(error);
+
+        return new WebApplicationException(builder.build());
+    }
+
     public void updateAccount(ACMEAccount account) throws Exception {
         database.updateAccount(account);
     }