diff --git a/ui/src/Components/MainModal/index.test.js b/ui/src/Components/MainModal/index.test.js
index 3f007c55e..4c117bd09 100644
--- a/ui/src/Components/MainModal/index.test.js
+++ b/ui/src/Components/MainModal/index.test.js
@@ -34,6 +34,7 @@ beforeEach(() => {
 afterEach(() => {
   jest.restoreAllMocks();
   fetchMock.reset();
+  document.body.className = "";
 });
 
 const MountedMainModal = () => {
@@ -111,8 +112,12 @@ describe("<MainModal />", () => {
   it("'modal-open' class is removed from body node after modal is hidden", () => {
     const tree = MountedMainModal();
     const toggle = tree.find(".nav-link");
+
     toggle.simulate("click");
+    expect(document.body.className.split(" ")).toContain("modal-open");
+
     toggle.simulate("click");
+    act(() => jest.runOnlyPendingTimers());
     expect(document.body.className.split(" ")).not.toContain("modal-open");
   });
 
diff --git a/ui/src/Components/ManagedSilence/DeleteSilence.test.js b/ui/src/Components/ManagedSilence/DeleteSilence.test.js
index 983ced60a..937b11a80 100644
--- a/ui/src/Components/ManagedSilence/DeleteSilence.test.js
+++ b/ui/src/Components/ManagedSilence/DeleteSilence.test.js
@@ -52,6 +52,7 @@ afterEach(() => {
   useFetchGet.mockReset();
   useFetchDelete.mockReset();
   clear();
+  document.body.className = "";
 });
 
 const MockOnHide = jest.fn();
diff --git a/ui/src/Components/Modal/index.js b/ui/src/Components/Modal/index.js
index 0f9af1893..6e8ff5b71 100644
--- a/ui/src/Components/Modal/index.js
+++ b/ui/src/Components/Modal/index.js
@@ -1,10 +1,7 @@
-import React, { Component } from "react";
+import React, { useRef, useEffect, useCallback } from "react";
 import ReactDOM from "react-dom";
 import PropTypes from "prop-types";
 
-import { observer } from "mobx-react";
-import { observable } from "mobx";
-
 import { disableBodyScroll, clearAllBodyScrollLocks } from "body-scroll-lock";
 
 import { HotKeys } from "react-hotkeys";
@@ -14,105 +11,76 @@ import {
   MountModalBackdrop,
 } from "Components/Animations/MountModal";
 
-const Modal = observer(
-  class Modal extends Component {
-    static propTypes = {
-      size: PropTypes.oneOf(["lg", "xl"]),
-      isOpen: PropTypes.bool.isRequired,
-      isUpper: PropTypes.bool,
-      toggleOpen: PropTypes.func.isRequired,
-      children: PropTypes.node.isRequired,
+const ModalInner = ({ size, isUpper, toggleOpen, children }) => {
+  const ref = useRef(null);
+
+  useEffect(() => {
+    document.body.classList.add("modal-open");
+    disableBodyScroll(ref.current);
+    return () => {
+      document.body.classList.remove("modal-open");
+      clearAllBodyScrollLocks();
     };
-    static defaultProps = {
-      size: "lg",
-      isUpper: false,
+  }, []);
+
+  const onRemount = useCallback(() => {
+    document.body.classList.add("modal-open");
+    disableBodyScroll(ref.current);
+  }, []);
+
+  useEffect(() => {
+    window.addEventListener("remountModal", onRemount);
+    return () => {
+      window.removeEventListener("remountModal", onRemount);
     };
+  }, [onRemount]);
 
-    constructor(props) {
-      super(props);
-      this.modalRef = React.createRef();
-      this.HotKeysRef = React.createRef();
-      this.lastIsOpen = observable.box(false);
-    }
+  return (
+    <HotKeys
+      innerRef={(r) => r && r.focus()}
+      keyMap={{ CLOSE: "Escape" }}
+      handlers={{ CLOSE: toggleOpen }}
+      className="modal-open"
+    >
+      <div ref={ref} className="modal d-block" role="dialog">
+        <div
+          className={`modal-dialog modal-${size} ${
+            isUpper ? "modal-upper shadow" : ""
+          }`}
+          role="document"
+        >
+          <div className="modal-content">{children}</div>
+        </div>
+      </div>
+    </HotKeys>
+  );
+};
 
-    toggleBodyClass = (isOpen) => {
-      document.body.classList.toggle("modal-open", isOpen);
-      if (isOpen) {
-        this.HotKeysRef.current.focus();
-        disableBodyScroll(this.modalRef.current);
-      } else {
-        clearAllBodyScrollLocks();
-      }
-      this.lastIsOpen.set(isOpen);
-    };
-
-    componentDidMount() {
-      const { isOpen } = this.props;
-      if (isOpen) {
-        this.toggleBodyClass(isOpen);
-      }
-    }
-
-    componentDidUpdate() {
-      const { isOpen } = this.props;
-      // we shouldn't update if modal is hidden and was hidden previously
-      // which can happen when the button gets re-rendered
-      if (this.lastIsOpen.get() === true || isOpen === true) {
-        this.toggleBodyClass(isOpen);
-      }
-    }
-
-    componentWillUnmount() {
-      const { isOpen } = this.props;
-
-      if (isOpen) {
-        this.toggleBodyClass(false);
-      }
-    }
-
-    render() {
-      const {
-        size,
-        isOpen,
-        isUpper,
-        toggleOpen,
-        children,
-        ...props
-      } = this.props;
-
-      return ReactDOM.createPortal(
-        <React.Fragment>
-          <MountModal
-            in={isOpen}
-            unmountOnExit
-            className="modal-open"
-            {...props}
-          >
-            <HotKeys
-              innerRef={this.HotKeysRef}
-              keyMap={{ CLOSE: "Escape" }}
-              handlers={{ CLOSE: toggleOpen }}
-            >
-              <div ref={this.modalRef} className="modal d-block" role="dialog">
-                <div
-                  className={`modal-dialog modal-${size} ${
-                    isUpper && "modal-upper shadow"
-                  }`}
-                  role="document"
-                >
-                  <div className="modal-content">{children}</div>
-                </div>
-              </div>
-            </HotKeys>
-          </MountModal>
-          <MountModalBackdrop in={isOpen} unmountOnExit>
-            <div className="modal-backdrop d-block" />
-          </MountModalBackdrop>
-        </React.Fragment>,
-        document.body
-      );
-    }
-  }
-);
+const Modal = ({ size, isOpen, isUpper, toggleOpen, children, ...props }) => {
+  return ReactDOM.createPortal(
+    <React.Fragment>
+      <MountModal in={isOpen} unmountOnExit {...props}>
+        <ModalInner size={size} isUpper={isUpper} toggleOpen={toggleOpen}>
+          {children}
+        </ModalInner>
+      </MountModal>
+      <MountModalBackdrop in={isOpen} unmountOnExit>
+        <div className="modal-backdrop d-block" />
+      </MountModalBackdrop>
+    </React.Fragment>,
+    document.body
+  );
+};
+Modal.propTypes = {
+  size: PropTypes.oneOf(["lg", "xl"]),
+  isOpen: PropTypes.bool.isRequired,
+  isUpper: PropTypes.bool,
+  toggleOpen: PropTypes.func.isRequired,
+  children: PropTypes.node.isRequired,
+};
+Modal.defaultProps = {
+  size: "lg",
+  isUpper: false,
+};
 
 export { Modal };
diff --git a/ui/src/Components/Modal/index.test.js b/ui/src/Components/Modal/index.test.js
index e7a560848..828e46285 100644
--- a/ui/src/Components/Modal/index.test.js
+++ b/ui/src/Components/Modal/index.test.js
@@ -16,15 +16,22 @@ const MountedModal = (isOpen) => {
 
 afterEach(() => {
   jest.resetAllMocks();
+  document.body.className = "";
 });
 
 describe("<Modal />", () => {
+  it("'modal-open' class is appended to MountModal container", () => {
+    const tree = MountedModal(true);
+    expect(tree.find("div").at(0).hasClass("modal-open")).toBe(true);
+  });
+
   it("'modal-open' class is appended to body node when modal is visible", () => {
     MountedModal(true);
     expect(document.body.className.split(" ")).toContain("modal-open");
   });
 
   it("'modal-open' class is not removed from body node after hidden modal is unmounted", () => {
+    document.body.classList.add("modal-open");
     const tree = MountedModal(false);
     tree.unmount();
     expect(document.body.className.split(" ")).toContain("modal-open");
@@ -51,9 +58,7 @@ describe("<Modal />", () => {
     const tree = MountedModal(isOpen);
     expect(document.body.className.split(" ")).toContain("modal-open");
 
-    isOpen = false;
-    // force update
-    tree.setProps({ style: {} });
+    tree.setProps({ isOpen: false });
     expect(document.body.className.split(" ")).toContain("modal-open");
   });
 
@@ -70,7 +75,10 @@ describe("<Modal />", () => {
 
   it("toggleOpen is called after pressing 'esc'", () => {
     const tree = MountedModal(true);
-    tree.simulate("keyDown", { key: "Escape", keyCode: 27, which: 27 });
+    tree
+      .find("div")
+      .at(0)
+      .simulate("keyDown", { key: "Escape", keyCode: 27, which: 27 });
     expect(fakeToggle).toHaveBeenCalled();
   });
 });
diff --git a/ui/src/Components/OverviewModal/index.test.js b/ui/src/Components/OverviewModal/index.test.js
index 18c250f8f..71ba77845 100644
--- a/ui/src/Components/OverviewModal/index.test.js
+++ b/ui/src/Components/OverviewModal/index.test.js
@@ -16,6 +16,10 @@ beforeEach(() => {
   alertStore = new AlertStore([]);
 });
 
+afterEach(() => {
+  document.body.className = "";
+});
+
 const MountedOverviewModal = () => {
   return mount(<OverviewModal alertStore={alertStore} />);
 };
@@ -80,9 +84,12 @@ describe("<OverviewModal />", () => {
 
   it("'modal-open' class is removed from body node after modal is hidden", () => {
     const tree = MountedOverviewModal();
-    const toggle = tree.find("div.navbar-brand");
-    toggle.simulate("click");
-    toggle.simulate("click");
+
+    tree.find("div.navbar-brand").simulate("click");
+    expect(document.body.className.split(" ")).toContain("modal-open");
+
+    tree.find("div.navbar-brand").simulate("click");
+    act(() => jest.runOnlyPendingTimers());
     expect(document.body.className.split(" ")).not.toContain("modal-open");
   });
 
diff --git a/ui/src/Components/SilenceModal/index.js b/ui/src/Components/SilenceModal/index.js
index 05c581fd7..3129dc00b 100644
--- a/ui/src/Components/SilenceModal/index.js
+++ b/ui/src/Components/SilenceModal/index.js
@@ -1,4 +1,4 @@
-import React, { useRef } from "react";
+import React from "react";
 import PropTypes from "prop-types";
 
 import { observer } from "mobx-react";
@@ -22,10 +22,9 @@ const SilenceModalContent = React.lazy(() =>
 
 const SilenceModal = observer(
   ({ alertStore, silenceFormStore, settingsStore }) => {
-    const modalRef = useRef();
-
     const onDeleteModalClose = React.useCallback(() => {
-      modalRef.current.toggleBodyClass(true);
+      const event = new CustomEvent("remountModal");
+      window.dispatchEvent(event);
     }, []);
 
     return (
@@ -46,7 +45,6 @@ const SilenceModal = observer(
           </TooltipWrapper>
         </li>
         <Modal
-          ref={modalRef}
           isOpen={silenceFormStore.toggle.visible}
           toggleOpen={silenceFormStore.toggle.toggle}
           onExited={silenceFormStore.data.resetProgress}
diff --git a/ui/src/Components/SilenceModal/index.test.js b/ui/src/Components/SilenceModal/index.test.js
index 38153aeb6..eb5228f31 100644
--- a/ui/src/Components/SilenceModal/index.test.js
+++ b/ui/src/Components/SilenceModal/index.test.js
@@ -32,6 +32,10 @@ beforeEach(() => {
   silenceFormStore = new SilenceFormStore();
 });
 
+afterEach(() => {
+  document.body.className = "";
+});
+
 const MountedSilenceModal = () => {
   return mount(
     <ThemeContext.Provider
@@ -131,8 +135,12 @@ describe("<SilenceModal />", () => {
   it("'modal-open' class is removed from body node after modal is hidden", () => {
     const tree = MountedSilenceModal();
     const toggle = tree.find(".nav-link");
+
     toggle.simulate("click");
+    expect(document.body.className.split(" ")).toContain("modal-open");
+
     toggle.simulate("click");
+    act(() => jest.runOnlyPendingTimers());
     expect(document.body.className.split(" ")).not.toContain("modal-open");
   });