diff --git a/types/mathjs/index.d.ts b/types/mathjs/index.d.ts
index 256abf31b1..99ecf9d68e 100644
--- a/types/mathjs/index.d.ts
+++ b/types/mathjs/index.d.ts
@@ -2,9 +2,10 @@
 // Project: https://mathjs.org/
 // Definitions by: Ilya Shestakov <https://github.com/siavol>,
 //                  Andy Patterson <https://github.com/andnp>,
-//                  Brad Besserman <https://github.com/bradbesserman>
-//                  Pawel Krol <https://github.com/pawkrol>
-//                  Charlee Li <https://github.com/charlee>
+//                  Brad Besserman <https://github.com/bradbesserman>,
+//                  Pawel Krol <https://github.com/pawkrol>,
+//                  Charlee Li <https://github.com/charlee>,
+//                  Mark Wiemer <https://github.com/mark-wiemer>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -3072,6 +3073,7 @@ declare namespace math {
         isSymbolNode?: boolean;
         isUpdateNode?: boolean;
         comment?: string;
+        content?: MathNode;
         op?: string;
         fn?: string;
         args?: MathNode[];
diff --git a/types/mathjs/mathjs-tests.ts b/types/mathjs/mathjs-tests.ts
index 5d94716104..bddb683df1 100644
--- a/types/mathjs/mathjs-tests.ts
+++ b/types/mathjs/mathjs-tests.ts
@@ -153,6 +153,12 @@ Expressions examples
         math.evaluate(['f = 3', 'g = 4', 'f * g']);
     }
 
+    // get content of a parenthesis node
+    {
+        const node = math.parse('(1)');
+        const innerNode = node.content;
+    }
+
     // scope can contain both variables and functions
     {
         const scope = { hello: (name: string) => `hello, ${name}!` };