diff --git a/packages/patternfly-4/react-core/src/components/Dropdown/Dropdown.tsx b/packages/patternfly-4/react-core/src/components/Dropdown/Dropdown.tsx
index 4cc061c65..86ee33ed3 100644
--- a/packages/patternfly-4/react-core/src/components/Dropdown/Dropdown.tsx
+++ b/packages/patternfly-4/react-core/src/components/Dropdown/Dropdown.tsx
@@ -23,7 +23,7 @@ export interface DropdownProps extends React.HTMLProps<HTMLDivElement> {
   /** Toggle for the dropdown, examples: <DropdownToggle> or <DropdownToggleCheckbox> */
   toggle: React.ReactElement<any>;
   /** Function callback called when user selects item */
-  onSelect?(event: React.SyntheticEvent<HTMLDivElement>): void;
+  onSelect?(event?: React.SyntheticEvent<HTMLDivElement>): void;
   /** Flag to indicate if the first dropdown item should gain initial focus, set false when adding
    * a specific auto-focus item (like a current selection) otherwise leave as true
    */
diff --git a/packages/patternfly-4/react-core/src/components/Dropdown/DropdownWithContext.tsx b/packages/patternfly-4/react-core/src/components/Dropdown/DropdownWithContext.tsx
index fe1ea2218..307e825e8 100644
--- a/packages/patternfly-4/react-core/src/components/Dropdown/DropdownWithContext.tsx
+++ b/packages/patternfly-4/react-core/src/components/Dropdown/DropdownWithContext.tsx
@@ -21,7 +21,7 @@ class DropdownWithContext extends React.Component<DropdownProps & InjectedOuiaPr
     isGrouped: false,
     position: DropdownPosition.left,
     direction: DropdownDirection.down,
-    onSelect: Function.prototype,
+    onSelect: (): void => undefined,
     autoFocus: true,
     ouiaComponentType: 'Dropdown'
   };

@@            Coverage Diff             @@
##           master    #3135      +/-   ##
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- Coverage   68.98%   68.98%   -0.01%     
==========================================
  Files         858      858              
  Lines       23612    23621       +9     
  Branches     1887     1889       +2     
==========================================
+ Hits        16288    16294       +6     
- Misses       6364     6366       +2     
- Partials      960      961       +1