diff --git a/spring-web/src/main/java/org/springframework/http/ProblemDetail.java b/spring-web/src/main/java/org/springframework/http/ProblemDetail.java
index a454c38d0c..3e45dfb10e 100644
--- a/spring-web/src/main/java/org/springframework/http/ProblemDetail.java
+++ b/spring-web/src/main/java/org/springframework/http/ProblemDetail.java
@@ -156,8 +156,12 @@ public class ProblemDetail {
 	/**
 	 * Set a "dynamic" property to be added to a generic {@link #getProperties()
 	 * properties map}.
+	 * <p>When Jackson JSON is present on the classpath, any properties set here
+	 * are rendered as top level key-value pairs in the output JSON. Otherwise,
+	 * they are rendered as a {@code "properties"} sub-map.
 	 * @param name the property name
 	 * @param value the property value
+	 * @see org.springframework.http.converter.json.ProblemDetailJacksonMixin
 	 */
 	public void setProperty(String name, Object value) {
 		this.properties = (this.properties != null ? this.properties : new LinkedHashMap<>());
@@ -214,6 +218,10 @@ public class ProblemDetail {
 	 * Return a generic map of properties that are not known ahead of time,
 	 * possibly {@code null} if no properties have been added. To add a property,
 	 * use {@link #setProperty(String, Object)}.
+	 * <p>When Jackson JSON is present on the classpath, the content of this map
+	 * is unwrapped and rendered as top level key-value pairs in the output JSON.
+	 * Otherwise, they are rendered as a {@code "properties"} sub-map.
+	 * @see org.springframework.http.converter.json.ProblemDetailJacksonMixin
 	 */
 	@Nullable
 	public Map<String, Object> getProperties() {
diff --git a/src/docs/asciidoc/web/webflux.adoc b/src/docs/asciidoc/web/webflux.adoc
index 580d7cb63d..3a9695e1a4 100644
--- a/src/docs/asciidoc/web/webflux.adoc
+++ b/src/docs/asciidoc/web/webflux.adoc
@@ -3525,9 +3525,9 @@ back on "application/problem+json".
 
 Applications can extend `ProblemDetail` with non-standard fields in one of two ways:
 
-. Add properties to the generic `properties` map in `ProblemDetail`. When using
-the Jackson library, this `properties` map is unwrapped and as top level JSON
-properties with the help of `ProblemDetailJacksonMixin`.
+. Add properties to the generic `properties` map in `ProblemDetail`. When the Jackson JSON
+library is present, this `properties` map is unwrapped and rendered as top level
+key-value pairs in the output JSON, with the help of `ProblemDetailJacksonMixin`.
 . Create a `ProblemDetail` subclass that defines the extra, non-standard fields.
 Subclasses can use a protected copy constructor in order to re-create an existing
 `ProblemDetail` as a subclass. This can be done centrally from an `@ControllerAdvice`