diff --git a/crates/oxc_linter/src/rules/unicorn/prefer_array_flat_map.rs b/crates/oxc_linter/src/rules/unicorn/prefer_array_flat_map.rs
index 89dc074564d7c..09b37c1e35293 100644
--- a/crates/oxc_linter/src/rules/unicorn/prefer_array_flat_map.rs
+++ b/crates/oxc_linter/src/rules/unicorn/prefer_array_flat_map.rs
@@ -68,11 +68,13 @@ impl Rule for PreferArrayFlatMap {
         }
 
         if let Some(first_arg) = flat_call_expr.arguments.first() {
-            if let Argument::NumericLiteral(number_lit) = first_arg {
-                if number_lit.raw.as_ref().unwrap() != "1" {
-                    return;
-                }
-            } else {
+            // `Array.prototype.flat` rounds down the argument.
+            // So `.flat(1.5)` is equivalent to `.flat(1)`.
+            // https://tc39.es/ecma262/#sec-array.prototype.flat
+            // https://tc39.es/ecma262/#sec-tointegerorinfinity
+            // https://tc39.es/ecma262/#eqn-truncate
+            #[expect(clippy::float_cmp)]
+            if !matches!(first_arg, Argument::NumericLiteral(lit) if lit.value.floor() == 1.0) {
                 return;
             }
         }
@@ -107,7 +109,13 @@ fn test() {
         ("const bar = [[1],[2],[3]].flat()", None),
         ("const bar = [1,2,3].map(i => [i]).sort().flat()", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(2)", None),
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(2.0)", None),
+        // Parsed as 0.9999999999999999. Rounds down to 0.
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(0.99999999999999994)", None),
+        // Parsed as 2.0.
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1.99999999999999989)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(1, null)", None),
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(-1)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(Infinity)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(Number.POSITIVE_INFINITY)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(Number.MAX_VALUE)", None),
@@ -117,11 +125,17 @@ fn test() {
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(+1)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(foo)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(foo.bar)", None),
-        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1.00)", None),
     ];
 
     let fail = vec![
         ("const bar = [[1],[2],[3]].map(i => [i]).flat()", None),
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1)", None),
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1.0)", None),
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1.00)", None),
+        // Parsed as 1.0.
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(0.99999999999999995)", None),
+        // Parsed as 1.9999999999999998. Rounds down to 1.
+        ("const bar = [[1],[2],[3]].map(i => [i]).flat(1.99999999999999988)", None),
         ("const bar = [[1],[2],[3]].map(i => [i]).flat(1,)", None),
         ("const bar = [1,2,3].map(i => [i]).flat()", None),
         ("const bar = [1,2,3].map((i) => [i]).flat()", None),
diff --git a/crates/oxc_linter/src/snapshots/unicorn_prefer_array_flat_map.snap b/crates/oxc_linter/src/snapshots/unicorn_prefer_array_flat_map.snap
index a0367d422972e..f90a8f7fc77e9 100644
--- a/crates/oxc_linter/src/snapshots/unicorn_prefer_array_flat_map.snap
+++ b/crates/oxc_linter/src/snapshots/unicorn_prefer_array_flat_map.snap
@@ -8,6 +8,41 @@ source: crates/oxc_linter/src/tester.rs
    ╰────
   help: Prefer `.flatMap(…)` over `.map(…).flat()`.
 
+  ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
+   ╭─[prefer_array_flat_map.tsx:1:13]
+ 1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(1)
+   ·             ───────────────────────────────────
+   ╰────
+  help: Prefer `.flatMap(…)` over `.map(…).flat()`.
+
+  ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
+   ╭─[prefer_array_flat_map.tsx:1:13]
+ 1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(1.0)
+   ·             ─────────────────────────────────────
+   ╰────
+  help: Prefer `.flatMap(…)` over `.map(…).flat()`.
+
+  ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
+   ╭─[prefer_array_flat_map.tsx:1:13]
+ 1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(1.00)
+   ·             ──────────────────────────────────────
+   ╰────
+  help: Prefer `.flatMap(…)` over `.map(…).flat()`.
+
+  ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
+   ╭─[prefer_array_flat_map.tsx:1:13]
+ 1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(0.99999999999999995)
+   ·             ─────────────────────────────────────────────────────
+   ╰────
+  help: Prefer `.flatMap(…)` over `.map(…).flat()`.
+
+  ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
+   ╭─[prefer_array_flat_map.tsx:1:13]
+ 1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(1.99999999999999988)
+   ·             ─────────────────────────────────────────────────────
+   ╰────
+  help: Prefer `.flatMap(…)` over `.map(…).flat()`.
+
   ⚠ eslint-plugin-unicorn(prefer-array-flat-map): `Array.flatMap` performs `Array.map` and `Array.flat` in one step.
    ╭─[prefer_array_flat_map.tsx:1:13]
  1 │ const bar = [[1],[2],[3]].map(i => [i]).flat(1,)