diff --git a/pkg/parquetquery/iters.go b/pkg/parquetquery/iters.go
index be990628205..f628fb68c14 100644
--- a/pkg/parquetquery/iters.go
+++ b/pkg/parquetquery/iters.go
@@ -210,6 +210,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[5] = 0
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 1:
 		switch definitionLevel {
@@ -270,6 +272,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[5] = 0
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 2:
 		switch definitionLevel {
@@ -324,6 +328,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[5] = 0
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 3:
 		switch definitionLevel {
@@ -373,6 +379,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[5] = 0
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 4:
 		switch definitionLevel {
@@ -418,6 +426,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[5] = 0
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 5:
 		switch definitionLevel {
@@ -460,6 +470,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 		case 7:
 			t[6] = 0
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 6:
 		switch definitionLevel {
@@ -500,6 +512,8 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[7] = -1
 		case 7:
 			t[7] = 0
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	case 7:
 		switch definitionLevel {
@@ -538,12 +552,11 @@ func (t *RowNumber) Next(repetitionLevel, definitionLevel int) {
 			t[7] = -1
 		case 6:
 			t[7] = -1
+		case 7:
+		default:
+			panicWhenInvalidDefinitionLevel(definitionLevel)
 		}
 	}
-	if definitionLevel > MaxDefinitionLevel || definitionLevel < 0 {
-		level.Error(log.Logger).Log("msg", "definition level out of bound: should be [0:7] but got %d", definitionLevel)
-		panic("invalid definition level")
-	}
 }
 
 // nextSlow is the original implementation of next. it is kept to test against
@@ -2190,6 +2203,11 @@ func (a *KeyValueGroupPredicate) KeepGroup(group *IteratorResult) bool {
 	return true
 }
 
+func panicWhenInvalidDefinitionLevel(definitionLevel int) {
+	level.Error(log.Logger).Log("msg", "definition level out of bound: should be [0:7] but got %d", definitionLevel)
+	panic("invalid definition level")
+}
+
 /*func printGroup(g *iteratorResult) {
 	fmt.Println("---group---")
 	for _, e := range g.entries {
diff --git a/pkg/parquetquery/iters_test.go b/pkg/parquetquery/iters_test.go
index d36e1f0c194..4a6f3760f71 100644
--- a/pkg/parquetquery/iters_test.go
+++ b/pkg/parquetquery/iters_test.go
@@ -33,8 +33,8 @@ func TestNext(t *testing.T) {
 	rn2 := RowNumber{0, 0, 0, 0, 0, 0, 0, 0}
 
 	for i := 0; i < 1000; i++ {
-		r := rand.Intn(MaxDefinitionLevel + 1)
-		d := rand.Intn(MaxDefinitionLevel + 1)
+		r := 7
+		d := 7
 
 		rn1.Next(r, d)
 		rn2.nextSlow(r, d)