diff --git a/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/lib/main.js b/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/lib/main.js
index fce3b5325d88..84cf85d3c6a4 100644
--- a/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/lib/main.js
+++ b/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/mean/lib/main.js
@@ -20,6 +20,7 @@
 
 // MODULES //
 
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var PINF = require( '@stdlib/constants/float64/pinf' );
 
 
@@ -61,7 +62,12 @@ var PINF = require( '@stdlib/constants/float64/pinf' );
 * // returns NaN
 */
 function mean( alpha, beta ) {
-	if ( alpha <= 0.0 || beta <= 0.0 ) {
+	if (
+		isnan( alpha ) ||
+		alpha <= 0.0 ||
+		isnan( beta ) ||
+		beta <= 0.0
+	) {
 		return NaN;
 	}
 	if ( alpha <= 1.0 ) {
diff --git a/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/median/lib/main.js b/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/median/lib/main.js
index bd926fd56d68..e2306b9e39ea 100644
--- a/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/median/lib/main.js
+++ b/lib/node_modules/@stdlib/stats/base/dists/pareto-type1/median/lib/main.js
@@ -20,6 +20,7 @@
 
 // MODULES //
 
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
 var pow = require( '@stdlib/math/base/special/pow' );
 
 
@@ -61,7 +62,12 @@ var pow = require( '@stdlib/math/base/special/pow' );
 * // returns NaN
 */
 function median( alpha, beta ) {
-	if ( alpha <= 0.0 || beta <= 0.0 ) {
+	if (
+		isnan( alpha ) ||
+		alpha <= 0.0 ||
+		isnan( beta ) ||
+		beta <= 0.0
+	) {
 		return NaN;
 	}
 	return beta * pow( 2.0, 1.0/alpha );