diff --git a/executor.go b/executor.go
index 65fe1b0c7..8a0215c0b 100644
--- a/executor.go
+++ b/executor.go
@@ -1304,7 +1304,10 @@ func (e *executor) executePercentile(ctx context.Context, qcx *Qcx, index string
 
 	// get nth
 	var nthFloat float64
-	nthArg := c.Args["nth"]
+	nthArg, ok := c.Args["nth"]
+	if !ok {
+		return ValCount{}, errors.New("Percentile(): nth required")
+	}
 	if nthArg == nil {
 		return ValCount{}, errors.New("Percentile(): nth required")
 	}
@@ -1314,10 +1317,10 @@ func (e *executor) executePercentile(ctx context.Context, qcx *Qcx, index string
 	case int64:
 		nthFloat = float64(nthArg)
 	default:
-		return ValCount{}, errors.Errorf("Percentile(): invalid nth='%v' of type (%[1]T), should be int64 or pql.Decimal", c.Args["nth"])
+		return ValCount{}, errors.Errorf("Percentile(): invalid nth='%v' of type (%[1]T), should be a number between 0 and 100 inclusive", c.Args["nth"])
 	}
 	if nthFloat < 0 || nthFloat > 100.0 {
-		return ValCount{}, errors.Errorf("Percentile(): invalid nth value (%f), should be between 0 and 100 inclusive", nthFloat)
+		return ValCount{}, errors.Errorf("Percentile(): invalid nth value (%f), should be a number between 0 and 100 inclusive", nthFloat)
 	}
 
 	// get field
diff --git a/executor_test.go b/executor_test.go
index 62a2784b1..1d69f5662 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -7137,7 +7137,7 @@ func variousQueriesOnPercentiles(t *testing.T, c *test.Cluster) {
 			csvVerifier: fmt.Sprintf("%d,1\n", expectedPercentile),
 		})
 	}
-	nthsInt := []int64{10}
+	nthsInt := []int64{0, 10, 100}
 	for _, nth := range nthsInt {
 		query := fmt.Sprintf(`Percentile(field="net_worth", filter=Row(val="foo"), nth=%d)`, nth)
 		expectedPercentile := getExpectedPercentile(nums, float64(nth))