diff --git a/types/mathjs/index.d.ts b/types/mathjs/index.d.ts
index a8ec6114eb..c72ca68941 100644
--- a/types/mathjs/index.d.ts
+++ b/types/mathjs/index.d.ts
@@ -1299,8 +1299,8 @@ declare namespace math {
          * traversed. The function must return a boolean.
          */
         filter(
-            x: Matrix | MathArray,
-            test: ((value: any, index: any, matrix: Matrix | MathArray) => Matrix | MathArray) | RegExp
+            x: Matrix | MathArray | string[],
+            test: ((value: any, index: any, matrix: Matrix | MathArray | string[]) => boolean) | RegExp
         ): Matrix | MathArray;
 
         /**
diff --git a/types/mathjs/mathjs-tests.ts b/types/mathjs/mathjs-tests.ts
index 0d21be817e..15d455e427 100644
--- a/types/mathjs/mathjs-tests.ts
+++ b/types/mathjs/mathjs-tests.ts
@@ -281,6 +281,12 @@ Matrices examples
       return value * value;
 	  });  // returns [1, 4, 9]
 	}
+
+	// filter matrix
+	{
+	  math.filter([6, -2, -1, 4, 3], function(x) { return x > 0; }); // returns [6, 4, 3]
+	  math.filter(["23", "foo", "100", "55", "bar"], /[0-9]+/); // returns ["23", "100", "55"]
+	}
 }
 
 /*