diff --git a/promql/engine.go b/promql/engine.go
index 83bbdeff89..e2092a8003 100644
--- a/promql/engine.go
+++ b/promql/engine.go
@@ -2874,7 +2874,7 @@ func btos(b bool) float64 {
 // result of the op operation.
 func shouldDropMetricName(op parser.ItemType) bool {
 	switch op {
-	case parser.ADD, parser.SUB, parser.DIV, parser.MUL, parser.POW, parser.MOD:
+	case parser.ADD, parser.SUB, parser.DIV, parser.MUL, parser.POW, parser.MOD, parser.ATAN2:
 		return true
 	default:
 		return false
diff --git a/promql/testdata/operators.test b/promql/testdata/operators.test
index 7056213c9e..df2311b9ba 100644
--- a/promql/testdata/operators.test
+++ b/promql/testdata/operators.test
@@ -477,10 +477,10 @@ load 5m
     trigNaN{} NaN
 
 eval instant at 5m trigy atan2 trigx
-    trigy{} 0.4636476090008061
+    {} 0.4636476090008061
 
 eval instant at 5m trigy atan2 trigNaN
-    trigy{} NaN
+    {} NaN
 
 eval instant at 5m 10 atan2 20
     0.4636476090008061