diff --git a/change/p-profiler-2020-10-19-14-14-38-master.json b/change/p-profiler-2020-10-19-14-14-38-master.json
new file mode 100644
index 0000000..8baef6c
--- /dev/null
+++ b/change/p-profiler-2020-10-19-14-14-38-master.json
@@ -0,0 +1,8 @@
+{
+  "type": "patch",
+  "comment": "make sure typing allows either prefix / customOutputPath",
+  "packageName": "p-profiler",
+  "email": "kchau@microsoft.com",
+  "dependentChangeType": "patch",
+  "date": "2020-10-19T21:14:38.490Z"
+}
diff --git a/src/index.ts b/src/index.ts
index df90680..ddc91d7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -23,9 +23,9 @@ const getTimeBasedFilename = (prefix: string) => {
 
 export interface ProfilerOptions {
   concurrency: number;
-  prefix: string;
-  outDir: string;
-  customOutputPath: string;
+  prefix?: string;
+  outDir?: string;
+  customOutputPath?: string;
 }
 
 export default class Profiler {