diff --git a/src/controllers/QueryGraphHandler/knowledge_graph.js b/src/controllers/QueryGraphHandler/knowledge_graph.js
index ff3f0f70..8023197e 100644
--- a/src/controllers/QueryGraphHandler/knowledge_graph.js
+++ b/src/controllers/QueryGraphHandler/knowledge_graph.js
@@ -80,7 +80,7 @@ module.exports = class KnowledgeGraph {
     _createEdge(record) {
         return {
             [helper._createUniqueEdgeID(record)]: {
-                predicate: "biolink:" + record["$reasoner_edge"].getQueryPredicate(),
+                predicate: "biolink:" + ((typeof record["$reasoner_edge"].getQueryPredicate() === "undefined") ? record["$association"].predicate : record["$reasoner_edge"].getQueryPredicate()),
                 subject: helper._getInputID(record),
                 object: helper._getOutputID(record),
                 attributes: this._createAttributes(record)
diff --git a/src/controllers/QueryGraphHandler/reverse.js b/src/controllers/QueryGraphHandler/reverse.js
index 9abb2ef9..6cbbaef8 100644
--- a/src/controllers/QueryGraphHandler/reverse.js
+++ b/src/controllers/QueryGraphHandler/reverse.js
@@ -8,12 +8,15 @@ module.exports = class EdgeReverse {
     }
 
     reverse(predicate) {
-        let modifiedPredicate = predicate.replace('_', ' ');
-        if (modifiedPredicate in this.data.slots) {
-            if ('inverse' in this.data.slots[modifiedPredicate]) {
-                return this.data.slots[modifiedPredicate].inverse.replace(' ', '_');
+        if (typeof predicate === "string") {
+            let modifiedPredicate = predicate.replace('_', ' ');
+            if (modifiedPredicate in this.data.slots) {
+                if ('inverse' in this.data.slots[modifiedPredicate]) {
+                    return this.data.slots[modifiedPredicate].inverse.replace(' ', '_');
+                }
             }
         }
+
         return undefined;
     }
 }
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