diff --git a/packages/mui-material/src/FilledInput/FilledInput.js b/packages/mui-material/src/FilledInput/FilledInput.js
index ab672ed77d02f8..8d2a6b1aa4588c 100644
--- a/packages/mui-material/src/FilledInput/FilledInput.js
+++ b/packages/mui-material/src/FilledInput/FilledInput.js
@@ -234,7 +234,7 @@ const FilledInput = React.forwardRef(function FilledInput(inProps, ref) {
 
   const componentsProps =
     slotProps ?? componentsPropsProp
-      ? deepmerge(slotProps ?? componentsPropsProp, filledInputComponentsProps)
+      ? deepmerge(filledInputComponentsProps, slotProps ?? componentsPropsProp)
       : filledInputComponentsProps;
 
   const RootSlot = slots.root ?? components.Root ?? FilledInputRoot;
diff --git a/packages/mui-material/src/FilledInput/FilledInput.test.js b/packages/mui-material/src/FilledInput/FilledInput.test.js
index e7ce5fde0068d7..cb79f65cbb5af3 100644
--- a/packages/mui-material/src/FilledInput/FilledInput.test.js
+++ b/packages/mui-material/src/FilledInput/FilledInput.test.js
@@ -1,6 +1,7 @@
 import * as React from 'react';
 import { expect } from 'chai';
 import { createRenderer, describeConformance } from '@mui-internal/test-utils';
+import { styled } from '@mui/material/styles';
 import FilledInput, { filledInputClasses as classes } from '@mui/material/FilledInput';
 import InputBase from '@mui/material/InputBase';
 
@@ -67,4 +68,10 @@ describe('<FilledInput />', () => {
     );
     expect(document.querySelector('[data-test=test]')).toHaveComputedStyle({ marginTop: '10px' });
   });
+
+  it('should not throw: "Maximum call stack size exceeded" if both slotProps and an adornment are passed', () => {
+    const Adornment = styled('div')({});
+    render(<FilledInput endAdornment={<Adornment />} slotProps={{}} />);
+    render(<FilledInput startAdornment={<Adornment />} slotProps={{}} />);
+  });
 });