diff --git a/.changeset/purple-queens-breathe.md b/.changeset/purple-queens-breathe.md
new file mode 100644
index 0000000000..04e030dc29
--- /dev/null
+++ b/.changeset/purple-queens-breathe.md
@@ -0,0 +1,5 @@
+---
+"@comet/admin": major
+---
+
+Delete "secondaryText" from "MenuItemClassKey"
diff --git a/packages/admin/admin/src/mui/menu/Item.tsx b/packages/admin/admin/src/mui/menu/Item.tsx
index f23cf11ecb..7f7f955ffd 100644
--- a/packages/admin/admin/src/mui/menu/Item.tsx
+++ b/packages/admin/admin/src/mui/menu/Item.tsx
@@ -1,144 +1,175 @@
-import { ComponentsOverrides, ListItem, ListItemIcon, ListItemProps, ListItemText, Theme } from "@mui/material";
-import { createStyles, WithStyles, withStyles } from "@mui/styles";
+import { ListItemButton, ListItemButtonProps, ListItemIcon, ListItemText } from "@mui/material";
+import { ComponentsOverrides, css, styled, Theme, useThemeProps } from "@mui/material/styles";
+import { ThemedComponentBaseProps } from "helpers/ThemedComponentBaseProps";
 import * as React from "react";
 
 import { MenuLevel } from "./CollapsibleItem";
 import { MenuContext } from "./Context";
 
-export type MenuItemClassKey = "root" | "level1" | "level2" | "hasIcon" | "hasSecondaryText" | "hasSecondaryAction";
+export type MenuItemClassKey = "root" | "level1" | "level2" | "hasIcon" | "hasSecondaryAction";
+
+type OwnerState = Pick<MenuItemProps, "level" | "icon" | "secondaryAction">;
 
 const colors = {
     textLevel1: "#242424",
     textLevel2: "#17181A",
 };
 
-const styles = (theme: Theme) =>
-    createStyles<MenuItemClassKey, MenuItemProps & MuiListItemProps>({
-        root: {
-            flexShrink: 0,
-            "&:after": {
-                content: "''",
-                position: "absolute",
-                top: 0,
-                right: 0,
-                bottom: 0,
-                width: 2,
-            },
-            "& [class*='MuiListItemIcon-root']": {
-                color: colors.textLevel1,
-                minWidth: 28,
-            },
-            "& [class*='MuiListItemText-inset']": {
-                paddingLeft: 28,
-            },
-            "& [class*='MuiSvgIcon-root']": {
-                fontSize: 16,
-            },
-        },
-        level1: {
-            borderBottom: `1px solid ${theme.palette.grey[50]}`,
-            boxSizing: "border-box",
-            color: colors.textLevel1,
-            paddingLeft: 20,
-            paddingRight: 20,
-            paddingTop: 16,
-            paddingBottom: 16,
-            "&[class*='Mui-selected']": {
-                backgroundColor: theme.palette.grey[50],
-                color: theme.palette.primary.main,
-                "&:after": {
-                    backgroundColor: theme.palette.primary.main,
-                },
-                "& [class*='MuiListItemIcon-root']": {
-                    color: theme.palette.primary.main,
-                },
-            },
-            "& [class*='MuiListItemText-primary']": {
-                fontWeight: theme.typography.fontWeightMedium,
-                fontSize: 16,
-                lineHeight: "20px",
-            },
-        },
-        level2: {
-            color: colors.textLevel2,
-            paddingLeft: 20,
-            paddingRight: 20,
-            paddingTop: 10,
-            paddingBottom: 10,
-            "&:last-child": {
-                borderBottom: `1px solid ${theme.palette.grey[50]}`,
-                boxSizing: "border-box",
-            },
-            "&[class*='Mui-selected']": {
-                backgroundColor: theme.palette.primary.main,
-                color: "#fff",
-                "&:after": {
-                    backgroundColor: theme.palette.primary.dark,
-                },
-                "&:hover": {
-                    backgroundColor: theme.palette.primary.dark,
-                },
-                "& [class*='MuiListItemText-primary']": {
-                    fontWeight: theme.typography.fontWeightBold,
-                },
-            },
-            "& [class*='MuiListItemText-root']": {
-                margin: 0,
-            },
-            "& [class*='MuiListItemText-primary']": {
-                fontWeight: theme.typography.fontWeightRegular,
-                fontSize: 14,
-                lineHeight: "20px",
-            },
-        },
-        hasIcon: {},
-        hasSecondaryText: {},
-        hasSecondaryAction: {
-            paddingRight: 18,
-        },
-    });
+const Root = styled(ListItemButton, {
+    name: "CometAdminMenuItem",
+    slot: "root",
+    overridesResolver({ ownerState }: { ownerState: OwnerState }, styles) {
+        return [
+            styles.root,
+            ownerState.level === 1 && styles.level1,
+            ownerState.level === 2 && styles.level2,
+            ownerState.icon && styles.hasIcon,
+            ownerState.secondaryAction && styles.hasSecondaryAction,
+        ];
+    },
+})<{ ownerState: OwnerState }>(
+    ({ theme, ownerState }) => css`
+        flex-shrink: 0;
+        flex-grow: 0;
+
+        &:after {
+            content: "";
+            position: absolute;
+            top: 0;
+            right: 0;
+            bottom: 0;
+            width: 2px;
+        }
+
+        .MuiListItemIcon-root {
+            color: ${colors.textLevel1};
+            min-width: 28px;
+        }
+
+        .MuiListItemText-inset {
+            padding-left: 28px;
+        }
+
+        .MuiSvgIcon-root {
+            font-size: 16px;
+        }
+
+        ${ownerState.level === 1 &&
+        css`
+            border-bottom: 1px solid ${theme.palette.grey[50]};
+            box-sizing: border-box;
+            color: ${colors.textLevel1};
+            padding-left: 20px;
+            padding-right: 20px;
+            padding-top: 16px;
+            padding-bottom: 16px;
+
+            &.Mui-selected {
+                background-color: ${theme.palette.grey[50]};
+                color: ${theme.palette.primary.main};
+
+                &:after {
+                    background-color: ${theme.palette.primary.main};
+                }
+                .MuiListItemIcon-root {
+                    color: ${theme.palette.primary.main};
+                }
+            }
+
+            .MuiListItemText-primary {
+                font-weight: ${theme.typography.fontWeightMedium};
+                font-size: 16px;
+                line-height: 20px;
+            }
+        `}
+
+        ${ownerState.level === 2 &&
+        css`
+            color: ${colors.textLevel2};
+            padding-left: 20px;
+            padding-right: 20px;
+            padding-top: 10px;
+            padding-bottom: 10px;
+
+            &:last-child {
+                border-bottom: 1px solid ${theme.palette.grey[50]};
+                box-sizing: border-box;
+            }
+
+            &.Mui-selected {
+                background-color: ${theme.palette.primary.main};
+                color: #fff;
+
+                &:after {
+                    background-color: ${theme.palette.primary.dark};
+                }
+                &:hover {
+                    background-color: ${theme.palette.primary.dark};
+                }
+                &.MuiListItemText-primary {
+                    font-weight: ${theme.typography.fontWeightBold};
+                }
+            }
 
-export interface MenuItemProps extends MenuLevel {
+            .MuiListItemText-root {
+                margin: 0;
+            }
+
+            .MuiListItemText-primary {
+                font-weight: ${theme.typography.fontWeightRegular};
+                font-size: 14px;
+                line-height: 20px;
+            }
+        `};
+
+        ${ownerState.secondaryAction &&
+        css`
+            padding-right: 18px;
+        `}
+    `,
+);
+
+export interface MenuItemProps extends ThemedComponentBaseProps<{ root: typeof ListItemButton }>, MenuLevel, ListItemButtonProps {
     primary: React.ReactNode;
     secondary?: React.ReactNode;
     icon?: React.ReactElement;
     secondaryAction?: React.ReactNode;
+    secondaryText?: boolean;
 }
 
-type MuiListItemProps = Pick<ListItemProps, Exclude<keyof ListItemProps, "innerRef" | "button">> & { component?: React.ElementType };
-
-const Item: React.FC<WithStyles<typeof styles> & MenuItemProps & MuiListItemProps> = ({
-    classes,
-    primary,
-    secondary,
-    icon,
-    level = 1,
-    secondaryAction,
-    ...otherProps
-}) => {
-    const context = React.useContext(MenuContext);
-    if (!context) throw new Error("Could not find context for menu");
-    if (level > 2) throw new Error("Maximum nesting level of 2 exceeded.");
+export function MenuItem(inProps: MenuItemProps) {
+    const {
+        primary,
+        icon,
+        level = 1,
+        secondaryAction,
+        slotProps,
+        ...otherProps
+    } = useThemeProps({
+        props: inProps,
+        name: "CometAdminMenuItem",
+    });
+
+    const ownerState: OwnerState = {
+        level,
+        icon,
+        secondaryAction,
+    };
 
     const hasIcon = !!icon;
 
-    const listItemClasses = [classes.root];
-    if (level === 1) listItemClasses.push(classes.level1);
-    if (level === 2) listItemClasses.push(classes.level2);
-    if (hasIcon) listItemClasses.push(classes.hasIcon);
-    if (secondary) listItemClasses.push(classes.hasSecondaryText);
-    if (secondaryAction) listItemClasses.push(classes.hasSecondaryAction);
+    const context = React.useContext(MenuContext);
+    if (!context) throw new Error("Could not find context for menu");
+    if (level > 2) throw new Error("Maximum nesting level of 2 exceeded.");
 
     return (
-        <ListItem component="div" button classes={{ root: listItemClasses.join(" ") }} {...otherProps}>
+        <Root {...slotProps?.root} ownerState={ownerState} {...otherProps}>
             {hasIcon && <ListItemIcon>{icon}</ListItemIcon>}
-            <ListItemText primary={primary} secondary={secondary} inset={!icon} />
+            <ListItemText primary={primary} inset={!icon} />
             {!!secondaryAction && secondaryAction}
-        </ListItem>
+        </Root>
     );
-};
-
-export const MenuItem = withStyles(styles, { name: "CometAdminMenuItem" })(Item);
+}
 
 declare module "@mui/material/styles" {
     interface ComponentNameToClassKey {
diff --git a/packages/admin/admin/src/mui/menu/ItemAnchorLink.tsx b/packages/admin/admin/src/mui/menu/ItemAnchorLink.tsx
index 7ef7a12bdc..e2273806c5 100644
--- a/packages/admin/admin/src/mui/menu/ItemAnchorLink.tsx
+++ b/packages/admin/admin/src/mui/menu/ItemAnchorLink.tsx
@@ -1,8 +1,10 @@
-import { ListItemProps } from "@mui/material/ListItem";
+import { ListItemButtonProps } from "@mui/material";
 import * as React from "react";
 
 import { MenuItem, MenuItemProps } from "./Item";
 
-export const MenuItemAnchorLink: React.FC<MenuItemProps & ListItemProps & React.HTMLProps<HTMLAnchorElement>> = (props) => (
+export const MenuItemAnchorLink: React.FC<MenuItemProps & ListItemButtonProps & React.HTMLProps<HTMLAnchorElement>> = (props) => (
+    // @ts-expect-error "component"-property is used as described in the documentation  https://mui.com/material-ui/react-list/, but type is missing in ListItemButtonProps
+
     <MenuItem selected={false} component="a" {...props} />
 );