diff --git a/clippy_lints/src/manual_unwrap_or_default.rs b/clippy_lints/src/manual_unwrap_or_default.rs
index 84fb183e3f79..451172db64e3 100644
--- a/clippy_lints/src/manual_unwrap_or_default.rs
+++ b/clippy_lints/src/manual_unwrap_or_default.rs
@@ -2,7 +2,7 @@ use rustc_errors::Applicability;
 use rustc_hir::def::Res;
 use rustc_hir::{Arm, Expr, ExprKind, HirId, LangItem, MatchSource, Pat, PatKind, QPath};
 use rustc_lint::{LateContext, LateLintPass, LintContext};
-use rustc_middle::ty::GenericArgKind;
+use rustc_middle::ty::{self, GenericArgKind};
 use rustc_session::declare_lint_pass;
 use rustc_span::sym;
 
@@ -148,6 +148,42 @@ fn handle<'tcx>(cx: &LateContext<'tcx>, if_let_or_match: IfLetOrMatch<'tcx>, exp
         && is_default_equivalent(cx, body_none)
         && let Some(receiver) = Sugg::hir_opt(cx, condition).map(Sugg::maybe_par)
     {
+        // We check if the expression is not a None variant
+        if let Some(none_def_id) = cx.tcx.lang_items().option_none_variant() {
+            if let ExprKind::Path(QPath::Resolved(_, path)) = &condition.kind {
+                if let Some(def_id) = path.res.opt_def_id() {
+                    if cx.tcx.parent(def_id) == none_def_id {
+                        return span_lint_and_sugg(
+                            cx,
+                            MANUAL_UNWRAP_OR_DEFAULT,
+                            expr.span,
+                            format!("{expr_name} can be simplified with `.unwrap_or_default()`"),
+                            "replace it with",
+                            format!("{receiver}::</* Type */>.unwrap_or_default()"),
+                            Applicability::HasPlaceholders,
+                        );
+                    }
+                }
+            }
+        }
+
+        // We check if the expression is not a method or function with a unspecified return type
+        if let ExprKind::MethodCall(_, expr, _, _) = &condition.kind {
+            if let ty::Adt(_, substs) = cx.typeck_results().expr_ty(expr).kind() {
+                if let Some(ok_type) = substs.first() {
+                    return span_lint_and_sugg(
+                        cx,
+                        MANUAL_UNWRAP_OR_DEFAULT,
+                        expr.span,
+                        format!("{expr_name} can be simplified with `.unwrap_or_default()`"),
+                        format!("explicit the type {ok_type} and replace your expression with"),
+                        format!("{receiver}.unwrap_or_default()"),
+                        Applicability::Unspecified,
+                    );
+                }
+            }
+        }
+
         // Machine applicable only if there are no comments present
         let applicability = if span_contains_comment(cx.sess().source_map(), expr.span) {
             Applicability::MaybeIncorrect
diff --git a/tests/ui/manual_unwrap_or_default.fixed b/tests/ui/manual_unwrap_or_default.fixed
index d6e736ba9cc2..c5dfd2eb01e7 100644
--- a/tests/ui/manual_unwrap_or_default.fixed
+++ b/tests/ui/manual_unwrap_or_default.fixed
@@ -72,3 +72,9 @@ fn issue_12569() {
         0
     };
 }
+
+fn issue_12670() {
+    let a: Option<i32> = None;
+    let _ = a.unwrap_or_default();
+    let _ = Some(99).unwrap_or_default();
+}
diff --git a/tests/ui/manual_unwrap_or_default.rs b/tests/ui/manual_unwrap_or_default.rs
index 462d5d90ee77..842a26f4fb12 100644
--- a/tests/ui/manual_unwrap_or_default.rs
+++ b/tests/ui/manual_unwrap_or_default.rs
@@ -96,3 +96,9 @@ fn issue_12569() {
         0
     };
 }
+
+fn issue_12670() {
+    let a: Option<i32> = None;
+    let _ = if let Some(x) = a { x } else { i32::default() };
+    let _ = if let Some(x) = Some(99) { x } else { i32::default() };
+}
diff --git a/tests/ui/manual_unwrap_or_default.stderr b/tests/ui/manual_unwrap_or_default.stderr
index 3f1da444301f..e327c27db6f6 100644
--- a/tests/ui/manual_unwrap_or_default.stderr
+++ b/tests/ui/manual_unwrap_or_default.stderr
@@ -62,5 +62,17 @@ LL | |             _ => 0,
 LL | |         },
    | |_________^ help: replace it with: `(*b).unwrap_or_default()`
 
-error: aborting due to 6 previous errors
+error: if let can be simplified with `.unwrap_or_default()`
+  --> tests/ui/manual_unwrap_or_default.rs:102:13
+   |
+LL |     let _ = if let Some(x) = a { x } else { i32::default() };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `a.unwrap_or_default()`
+
+error: if let can be simplified with `.unwrap_or_default()`
+  --> tests/ui/manual_unwrap_or_default.rs:103:13
+   |
+LL |     let _ = if let Some(x) = Some(99) { x } else { i32::default() };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `Some(99).unwrap_or_default()`
+
+error: aborting due to 8 previous errors
 
diff --git a/tests/ui/manual_unwrap_or_default_unfixable.rs b/tests/ui/manual_unwrap_or_default_unfixable.rs
new file mode 100644
index 000000000000..d82dc8688d9c
--- /dev/null
+++ b/tests/ui/manual_unwrap_or_default_unfixable.rs
@@ -0,0 +1,10 @@
+//@no-rustfix
+fn issue_12670() {
+    #[allow(clippy::match_result_ok)]
+    let _ = if let Some(x) = "1".parse().ok() {
+        x
+    } else {
+        i32::default()
+    };
+    let _ = if let Some(x) = None { x } else { i32::default() };
+}
diff --git a/tests/ui/manual_unwrap_or_default_unfixable.stderr b/tests/ui/manual_unwrap_or_default_unfixable.stderr
new file mode 100644
index 000000000000..a6027a33638b
--- /dev/null
+++ b/tests/ui/manual_unwrap_or_default_unfixable.stderr
@@ -0,0 +1,17 @@
+error: if let can be simplified with `.unwrap_or_default()`
+  --> tests/ui/manual_unwrap_or_default_unfixable.rs:4:30
+   |
+LL |     let _ = if let Some(x) = "1".parse().ok() {
+   |                              ^^^^^^^^^^^ help: explicit the type i32 and replace your expression with: `"1".parse().ok().unwrap_or_default()`
+   |
+   = note: `-D clippy::manual-unwrap-or-default` implied by `-D warnings`
+   = help: to override `-D warnings` add `#[allow(clippy::manual_unwrap_or_default)]`
+
+error: if let can be simplified with `.unwrap_or_default()`
+  --> tests/ui/manual_unwrap_or_default_unfixable.rs:9:13
+   |
+LL |     let _ = if let Some(x) = None { x } else { i32::default() };
+   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `None::</* Type */>.unwrap_or_default()`
+
+error: aborting due to 2 previous errors
+