diff --git a/types/p5/global.d.ts b/types/p5/global.d.ts
index 13bcd8acc4..4c8b98b2cd 100644
--- a/types/p5/global.d.ts
+++ b/types/p5/global.d.ts
@@ -5419,8 +5419,8 @@ declare global {
    *   @return the random number
    */
   function randomGaussian(
-    mean: number,
-    sd: number
+    mean?: number,
+    sd?: number
   ): number;
 
   /**