diff --git a/examples/json_queries/aggregates.json b/examples/json_queries/aggregates.json
index 7eb2119..335ea14 100644
--- a/examples/json_queries/aggregates.json
+++ b/examples/json_queries/aggregates.json
@@ -4,9 +4,11 @@
     "sum": "?v$sum",
     "min": "?v$min",
     "max": "?v$max",
-    "avg": "?v$avg$var:average"
+    "avg": "?v$avg$var:average",
+    "value_sum": "?value$sum"
   },
   "$where": [
-    "VALUES (?v) { (10.5) (20.5) }"
+    "VALUES (?v) { (10.5) (20.5) }",
+    "?id schema:value ?value"
   ]
 }
diff --git a/examples/json_transformed/aggregates.json b/examples/json_transformed/aggregates.json
index 0653bd5..929261d 100644
--- a/examples/json_transformed/aggregates.json
+++ b/examples/json_transformed/aggregates.json
@@ -4,6 +4,7 @@
      "count": 2,
      "max": 20.5,
      "min": 10.5,
-     "sum": 31
+     "sum": 31,
+     "value_sum": 42
   }
 ]
\ No newline at end of file
diff --git a/examples/sparql_output/aggregates.json b/examples/sparql_output/aggregates.json
index 8a5b06a..f777776 100644
--- a/examples/sparql_output/aggregates.json
+++ b/examples/sparql_output/aggregates.json
@@ -1,7 +1,7 @@
 {
   "head": {
     "link": [],
-    "vars": ["total", "sum_v", "min_v", "max_v", "average"]
+    "vars": ["total", "sum_v", "min_v", "max_v", "average", "sum_value"]
   },
   "results": {
     "distinct": false,
@@ -31,6 +31,11 @@
         "type": "typed-literal",
         "datatype": "http://www.w3.org/2001/XMLSchema#decimal",
         "value": "15.5"
+      },
+      "sum_value": {
+        "type": "typed-literal",
+        "datatype": "http://www.w3.org/2001/XMLSchema#decimal",
+        "value": "42"
       }
     }]
   }
diff --git a/examples/sparql_queries/aggregates.rq b/examples/sparql_queries/aggregates.rq
index ee22a2e..713453e 100644
--- a/examples/sparql_queries/aggregates.rq
+++ b/examples/sparql_queries/aggregates.rq
@@ -1,4 +1,5 @@
-  SELECT DISTINCT (COUNT(DISTINCT ?v) AS ?total) (SUM(?v) AS ?sum_v) (MIN(?v) AS ?min_v) (MAX(?v) AS ?max_v) (AVG(?v) AS ?average)
+  SELECT DISTINCT (COUNT(DISTINCT ?v) AS ?total) (SUM(?v) AS ?sum_v) (MIN(?v) AS ?min_v) (MAX(?v) AS ?max_v) (AVG(?v) AS ?average) (SUM(?value) AS ?sum_value)
   WHERE {
-    VALUES (?v) { (10.5) (20.5) }
+    VALUES (?v) { (10.5) (20.5) }.
+    ?id schema:value ?value
   }
diff --git a/src/main.mjs b/src/main.mjs
index 08a0fe4..b2f6412 100644
--- a/src/main.mjs
+++ b/src/main.mjs
@@ -326,7 +326,7 @@ function manageProtoKey(proto, vars = [], filters = [], wheres = [],
 
         const aggrWhat = is$ ? id : originalId;
         if (aggregate && !givenVar) {
-            id = is$ ? originalId : `?${aggregate}_${originalId.replace('?', '')}`;
+            id = `?${aggregate}_${aggrWhat.replace('?', '')}`;
         }
 
         // assign a clean id to the prototype