diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java b/processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java
index 163c390b66..358b08f8ec 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/model/PropertyMapping.java
@@ -681,7 +681,10 @@ private boolean targetDeclaringTypeIsNullMarked() {
                 return false;
             }
             Element declaring = targetElement.getEnclosingElement();
-            if ( !( declaring instanceof TypeElement ) ) {
+            while ( declaring != null && !( declaring instanceof TypeElement ) ) {
+                declaring = declaring.getEnclosingElement();
+            }
+            if ( declaring == null ) {
                 return false;
             }
             return ctx.getTypeFactory().getType( declaring.asType() ).isNullMarked();
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/ErroneousIssue4079Mapper.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/ErroneousIssue4079Mapper.java
new file mode 100644
index 0000000000..763fd99683
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/ErroneousIssue4079Mapper.java
@@ -0,0 +1,15 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._4079;
+
+import org.jspecify.annotations.NullMarked;
+import org.mapstruct.Mapper;
+
+@Mapper
+@NullMarked
+public interface ErroneousIssue4079Mapper {
+    Target map(Source source);
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Issue4079Test.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Issue4079Test.java
new file mode 100644
index 0000000000..52da98ada8
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Issue4079Test.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._4079;
+
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.ProcessorTest;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.WithJSpecify;
+import org.mapstruct.ap.testutil.compilation.annotation.CompilationResult;
+import org.mapstruct.ap.testutil.compilation.annotation.Diagnostic;
+import org.mapstruct.ap.testutil.compilation.annotation.ExpectedCompilationOutcome;
+import org.mapstruct.ap.testutil.runner.GeneratedSource;
+
+@IssueKey( "4079" )
+@WithJSpecify
+public class Issue4079Test {
+
+    @RegisterExtension
+    final GeneratedSource generatedSource = new GeneratedSource();
+
+    @ProcessorTest
+    @WithClasses( { ErroneousIssue4079Mapper.class, Source.class, Target.class } )
+    @ExpectedCompilationOutcome(value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(type = ErroneousIssue4079Mapper.class,
+                kind = javax.tools.Diagnostic.Kind.ERROR,
+                message = "Can't map potentially nullable source property \"nested\" to @NonNull " +
+                    "constructor parameter \"nested\". Consider adding a defaultValue or " +
+                    "defaultExpression.")
+        })
+    public void nullableSourceToNonNullConstructorParamUnderNullMarkedShouldFail() {
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Source.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Source.java
new file mode 100644
index 0000000000..f02d11f764
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Source.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._4079;
+
+import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
+
+@NullMarked
+public class Source {
+    private final @Nullable Nested nested;
+
+    public Source(@Nullable Nested nested) {
+        this.nested = nested;
+    }
+
+    public @Nullable Nested getNested() {
+        return nested;
+    }
+
+    public static class Nested {
+        private final String foo;
+
+        public Nested(String foo) {
+            this.foo = foo;
+        }
+
+        public String getFoo() {
+            return foo;
+        }
+    }
+}
diff --git a/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Target.java b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Target.java
new file mode 100644
index 0000000000..612d25c896
--- /dev/null
+++ b/processor/src/test/java/org/mapstruct/ap/test/bugs/_4079/Target.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._4079;
+
+import org.jspecify.annotations.NullMarked;
+
+@NullMarked
+public class Target {
+    private final Nested nested;
+
+    public Target(Nested nested) {
+        this.nested = nested;
+    }
+
+    public Nested getNested() {
+        return nested;
+    }
+
+    public static class Nested {
+        private final String foo;
+
+        public Nested(String foo) {
+            this.foo = foo;
+        }
+
+        public String getFoo() {
+            return foo;
+        }
+    }
+}