diff --git a/src/components/ActionButton.tsx b/src/components/ActionButton.tsx
index 7377dcb6..4b21ecde 100644
--- a/src/components/ActionButton.tsx
+++ b/src/components/ActionButton.tsx
@@ -51,6 +51,7 @@ class ActionButton extends React.Component<Props> {
                 <Button
                     ref={this.buttonRef}
                     intent={Intent.PRIMARY}
+                    onMouseDown={(e) => e.preventDefault()} // prevent focus
                     onClick={(): void => this.props.onAction()}
                     disabled={this.props.enabled === false}
                     className="no-box-shadow"
diff --git a/src/components/OpenFileButton.tsx b/src/components/OpenFileButton.tsx
index 28402120..bf8ac93c 100644
--- a/src/components/OpenFileButton.tsx
+++ b/src/components/OpenFileButton.tsx
@@ -114,6 +114,7 @@ class OpenFileButton extends React.Component<Props> {
                                         ? { pointerEvents: 'none' }
                                         : undefined
                                 }
+                                onMouseDown={(e) => e.preventDefault()} // prevent focus
                                 // onClick={this.props.onClick}
                                 // breaks Dropzone when this.props.onClick is undefined
                                 // so we have to do it the long way