diff --git a/src/index.d.ts b/src/index.d.ts
index fe1ec7a..5113e30 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,13 +1,40 @@
 // Initial typings by dmk99 - https://github.com/jcmcneal/react-step-wizard/issues/31#issuecomment-505399131
 import * as React from "react"
 
+export interface StepWizardTransitionProps {
+    enterRight?: string;
+    enterLeft?: string;
+    exitRight?: string;
+    exitLeft?: string;
+    intro?: string;
+}
+
+
+export interface StepWizardInstanceProps {
+    getHash: () => string;
+    getTransitions: () => StepWizardTransitionProps;
+    onHashChange: () => void;
+    isInvalidStep: (next: number) => boolean;
+    setActiveStep: (next: number) => void;
+    currentStep: number;
+    totalSteps: number;
+    getSteps: () => JSX.Element[] | React.ReactElement[];
+    firstStep: () => void;
+    lastStep: () => void;
+    nextStep: () => void;
+    previousStep: () => void;
+    goToStep: (step: number) => void;
+    goToNamedStep: (stepName: string) => void;
+    updateHash: (activeHash: string) => void;
+}
+
 export type StepWizardProps = Partial<{
   className: string
 
   hashKey: string
   stepName: string
   initialStep: number
-  instance: (wizard: StepWizardProps) => void
+  instance: (wizard: StepWizardInstanceProps) => void
   isHashEnabled: boolean
   isLazyMount: boolean
   nav: JSX.Element
@@ -17,13 +44,7 @@ export type StepWizardProps = Partial<{
     activeStep: number
   }) => void
 
-  transitions: {
-    enterRight?: string
-    enterLeft?: string
-    exitRight?: string
-    exitLeft?: string
-    intro?: string
-  }
+  transitions: StepWizardTransitionProps;
 
   children: JSX.Element | JSX.Element[] | React.ReactElement
 }>