diff --git a/clippy_lints/src/manual_map.rs b/clippy_lints/src/manual_map.rs
index e399c8fda55e..04ca35f9ca34 100644
--- a/clippy_lints/src/manual_map.rs
+++ b/clippy_lints/src/manual_map.rs
@@ -1,10 +1,11 @@
 use crate::utils::{
     is_type_diagnostic_item, match_def_path, paths, peel_hir_expr_refs, peel_mid_ty_refs_is_mutable,
-    snippet_with_applicability, span_lint_and_sugg,
+    snippet_with_applicability, span_lint_and_sugg, match_var, is_allowed,
 };
+use crate::{matches::MATCH_AS_REF, map_unit_fn::OPTION_MAP_UNIT_FN};
 use rustc_ast::util::parser::PREC_POSTFIX;
 use rustc_errors::Applicability;
-use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, Path, QPath};
+use rustc_hir::{Arm, BindingAnnotation, Block, Expr, ExprKind, Mutability, Pat, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
 use rustc_middle::lint::in_external_macro;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -88,6 +89,11 @@ impl LateLintPass<'_> for ManualMap {
                 None => return,
             };
 
+            if cx.typeck_results().expr_ty(some_expr) == cx.tcx.types.unit
+                && !is_allowed(cx, OPTION_MAP_UNIT_FN, expr.hir_id) {
+                    return;
+                }
+
             // Determine which binding mode to use.
             let explicit_ref = some_pat.contains_explicit_ref_binding();
             let binding_mutability = explicit_ref.or(if ty_ref_count != pat_ref_count {
@@ -118,6 +124,10 @@ impl LateLintPass<'_> for ManualMap {
                 if let Some(func) = can_pass_as_func(cx, some_binding, some_expr) {
                     snippet_with_applicability(cx, func.span, "..", &mut app).into_owned()
                 } else {
+                    if match_var(some_expr, some_binding.name) && !is_allowed(cx, MATCH_AS_REF, expr.hir_id) && binding_mutability.is_some() {
+                        return;
+                    }
+
                     // `ref` and `ref mut` annotations were handled earlier.
                     let annotation = if matches!(annotation, BindingAnnotation::Mutable) {
                         "mut "
@@ -161,10 +171,7 @@ impl LateLintPass<'_> for ManualMap {
 fn can_pass_as_func(cx: &LateContext<'tcx>, binding: Ident, expr: &'tcx Expr<'_>) -> Option<&'tcx Expr<'tcx>> {
     match expr.kind {
         ExprKind::Call(func, [arg])
-            if matches!(arg.kind,
-                ExprKind::Path(QPath::Resolved(None, Path { segments: [path], ..}))
-                if path.ident == binding
-            ) && cx.typeck_results().expr_adjustments(arg).is_empty() =>
+            if match_var(arg, binding.name) && cx.typeck_results().expr_adjustments(arg).is_empty() =>
         {
             Some(func)
         },
diff --git a/tests/ui/manual_map_option.fixed b/tests/ui/manual_map_option.fixed
index 6cb9a37b2300..7afeba759eab 100644
--- a/tests/ui/manual_map_option.fixed
+++ b/tests/ui/manual_map_option.fixed
@@ -32,9 +32,16 @@ fn main() {
 
     Some(0).map(|x| x + x);
 
+    #[warn(clippy::option_map_unit_fn)]
+    match &mut Some(String::new()) {
+        Some(x) => Some(x.push_str("")),
+        None => None,
+    };
+
+    #[allow(clippy::option_map_unit_fn)]
     Some(String::new()).as_mut().map(|x| x.push_str(""));
 
-    Some(String::new()).as_ref().map(|x| &**x);
+    Some(String::new()).as_ref().map(|x| x.len());
 
     Some(String::new()).as_ref().map(|x| x.is_empty());
 
diff --git a/tests/ui/manual_map_option.rs b/tests/ui/manual_map_option.rs
index b9753060b993..f8b31121e5b2 100644
--- a/tests/ui/manual_map_option.rs
+++ b/tests/ui/manual_map_option.rs
@@ -66,13 +66,20 @@ fn main() {
         &&_ => None,
     };
 
+    #[warn(clippy::option_map_unit_fn)]
     match &mut Some(String::new()) {
         Some(x) => Some(x.push_str("")),
         None => None,
     };
 
+    #[allow(clippy::option_map_unit_fn)]
     match &mut Some(String::new()) {
-        Some(ref x) => Some(&**x),
+        Some(x) => Some(x.push_str("")),
+        None => None,
+    };
+
+    match &mut Some(String::new()) {
+        Some(ref x) => Some(x.len()),
         None => None,
     };
 
diff --git a/tests/ui/manual_map_option.stderr b/tests/ui/manual_map_option.stderr
index f8e1bda83b25..08186b6ad9d7 100644
--- a/tests/ui/manual_map_option.stderr
+++ b/tests/ui/manual_map_option.stderr
@@ -101,7 +101,7 @@ LL | |     };
    | |_____^ help: try this: `Some(0).map(|x| x + x)`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:69:5
+  --> $DIR/manual_map_option.rs:76:5
    |
 LL | /     match &mut Some(String::new()) {
 LL | |         Some(x) => Some(x.push_str("")),
@@ -110,16 +110,16 @@ LL | |     };
    | |_____^ help: try this: `Some(String::new()).as_mut().map(|x| x.push_str(""))`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:74:5
+  --> $DIR/manual_map_option.rs:81:5
    |
 LL | /     match &mut Some(String::new()) {
-LL | |         Some(ref x) => Some(&**x),
+LL | |         Some(ref x) => Some(x.len()),
 LL | |         None => None,
 LL | |     };
-   | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| &**x)`
+   | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.len())`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:79:5
+  --> $DIR/manual_map_option.rs:86:5
    |
 LL | /     match &mut &Some(String::new()) {
 LL | |         Some(x) => Some(x.is_empty()),
@@ -128,7 +128,7 @@ LL | |     };
    | |_____^ help: try this: `Some(String::new()).as_ref().map(|x| x.is_empty())`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:84:5
+  --> $DIR/manual_map_option.rs:91:5
    |
 LL | /     match Some((0, 1, 2)) {
 LL | |         Some((x, y, z)) => Some(x + y + z),
@@ -137,7 +137,7 @@ LL | |     };
    | |_____^ help: try this: `Some((0, 1, 2)).map(|(x, y, z)| x + y + z)`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:89:5
+  --> $DIR/manual_map_option.rs:96:5
    |
 LL | /     match Some([1, 2, 3]) {
 LL | |         Some([first, ..]) => Some(first),
@@ -146,7 +146,7 @@ LL | |     };
    | |_____^ help: try this: `Some([1, 2, 3]).map(|[first, ..]| first)`
 
 error: manual implementation of `Option::map`
-  --> $DIR/manual_map_option.rs:94:5
+  --> $DIR/manual_map_option.rs:101:5
    |
 LL | /     match &Some((String::new(), "test")) {
 LL | |         Some((x, y)) => Some((y, x)),