diff --git a/src/parser.js b/src/parser.js
index a6d4223e..34906054 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -585,7 +585,7 @@ const parser = (() => {
                 type: 'function',
                 value: '(',
                 procedure: { type: 'variable', value: 'exists' },
-                arguments: [left]
+                arguments: [JSON.parse(JSON.stringify(left))]
             };
             this.then = left;
             this.else = expression(0);
diff --git a/test/test-suite/groups/coalescing-operator/case013.json b/test/test-suite/groups/coalescing-operator/case013.json
new file mode 100644
index 00000000..0f32ae7f
--- /dev/null
+++ b/test/test-suite/groups/coalescing-operator/case013.json
@@ -0,0 +1,7 @@
+{
+    "description": "array predicate on lhs exists, should return lhs value",
+    "expr": "foo.blah[0] ?? 42",
+    "dataset": "dataset0",
+    "bindings": {},
+    "result": {"baz": {"fud": "hello"}}
+}
diff --git a/test/test-suite/groups/coalescing-operator/case014.json b/test/test-suite/groups/coalescing-operator/case014.json
new file mode 100644
index 00000000..c9b1f463
--- /dev/null
+++ b/test/test-suite/groups/coalescing-operator/case014.json
@@ -0,0 +1,7 @@
+{
+    "description": "array predicate on lhs does not exist, should return rhs value",
+    "expr": "foo.blah[5] ?? 42",
+    "dataset": "dataset0",
+    "bindings": {},
+    "result": 42
+}