diff --git a/src/Exceptions/UnsupportedQueryGrammarException.php b/src/Exceptions/UnsupportedQueryGrammarException.php
new file mode 100644
index 0000000..8742100
--- /dev/null
+++ b/src/Exceptions/UnsupportedQueryGrammarException.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace ProcessMaker\Query\Exceptions;
+
+use Exception;
+
+class UnsupportedQueryGrammarException extends Exception
+{
+    public function __construct(
+        $message = 'Unsupported query grammar for handling JSON fields.',
+        $code = 0,
+        Exception $previous = null
+    ) {
+        parent::__construct($message, $code, $previous);
+    }
+}
diff --git a/src/FunctionCall.php b/src/FunctionCall.php
index 59b0fc8..9e03b00 100644
--- a/src/FunctionCall.php
+++ b/src/FunctionCall.php
@@ -35,7 +35,13 @@ public function field()
     {
         $params = [];
         foreach ($this->params as $param) {
-            $params[] = $param->toEloquent();
+            $eloquentParam = $param->toEloquent();
+            if (is_object($eloquentParam)) {
+                $grammar = DB::connection()->getQueryGrammar();
+                $eloquentParam = $eloquentParam->getValue($grammar);
+            }
+
+            $params[] = $eloquentParam;
         }
 
         return $this->name . '(' . implode(',', $params) . ')';
diff --git a/src/JsonField.php b/src/JsonField.php
index 4b76ce5..16abc06 100644
--- a/src/JsonField.php
+++ b/src/JsonField.php
@@ -2,10 +2,10 @@
 
 namespace ProcessMaker\Query;
 
-use Exception;
 use Illuminate\Database\Query\Grammars\MySqlGrammar;
 use Illuminate\Database\Query\Grammars\SQLiteGrammar;
 use Illuminate\Support\Facades\DB;
+use ProcessMaker\Query\Exceptions\UnsupportedQueryGrammarException;
 
 class JsonField extends BaseField
 {
@@ -29,7 +29,7 @@ public function toEloquent($connection = null)
         } elseif (is_a($grammar, SQLiteGrammar::class)) {
             return $connection->raw((new \ProcessMaker\Query\Grammars\SQLiteGrammar)->wrapJsonSelector($value));
         } else {
-            throw new Exception('Unsupported query grammar for handling JSON fields.');
+            throw new UnsupportedQueryGrammarException();
         }
     }
 }