diff --git a/pkg/yqlib/operator_add.go b/pkg/yqlib/operator_add.go
index 4b10585e..90ccb9b5 100644
--- a/pkg/yqlib/operator_add.go
+++ b/pkg/yqlib/operator_add.go
@@ -183,7 +183,7 @@ func addMaps(target *CandidateNode, lhsC *CandidateNode, rhsC *CandidateNode) {
 		key := rhs.Content[index]
 		value := rhs.Content[index+1]
 		log.Debug("finding %v", key.Value)
-		indexInLHS := findInArray(target.Node, key)
+		indexInLHS := findKeyInMap(target.Node, key)
 		log.Debug("indexInLhs %v", indexInLHS)
 		if indexInLHS < 0 {
 			// not in there, append it
diff --git a/pkg/yqlib/operator_add_test.go b/pkg/yqlib/operator_add_test.go
index 17d7969e..a98e3faf 100644
--- a/pkg/yqlib/operator_add_test.go
+++ b/pkg/yqlib/operator_add_test.go
@@ -14,6 +14,14 @@ var addOperatorScenarios = []expressionScenario{
 			"D0, P[1 a], (!!int)::3\n",
 		},
 	},
+	{
+		skipDoc:    true,
+		document:   `a: key`,
+		expression: `. += {"key": "b"}`,
+		expected: []string{
+			"D0, P[], (!!map)::a: key\nkey: b\n",
+		},
+	},
 	{
 		skipDoc:    true,
 		document:   `[[c], [b]]`,