diff --git a/spring-restdocs-core/src/main/java/org/springframework/restdocs/request/AbstractParametersSnippet.java b/spring-restdocs-core/src/main/java/org/springframework/restdocs/request/AbstractParametersSnippet.java
index 9d97737d..f2d5bd99 100644
--- a/spring-restdocs-core/src/main/java/org/springframework/restdocs/request/AbstractParametersSnippet.java
+++ b/spring-restdocs-core/src/main/java/org/springframework/restdocs/request/AbstractParametersSnippet.java
@@ -124,7 +124,7 @@ public abstract class AbstractParametersSnippet extends TemplatedSnippet {
 		}
 		else {
 			undocumentedParameters = new HashSet<>(actualParameters);
-			undocumentedParameters.removeAll(expectedParameters);
+			undocumentedParameters.removeAll(this.descriptorsByName.keySet());
 		}
 		Set<String> missingParameters = new HashSet<>(expectedParameters);
 		missingParameters.removeAll(actualParameters);
diff --git a/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/PathParametersSnippetTests.java b/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/PathParametersSnippetTests.java
index eac8c9d1..054ed7bc 100644
--- a/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/PathParametersSnippetTests.java
+++ b/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/PathParametersSnippetTests.java
@@ -99,6 +99,24 @@ public class PathParametersSnippetTests extends AbstractSnippetTests {
 								"/{a}").build());
 	}
 
+	@Test
+	public void presentOptionalPathParameter() throws IOException {
+		this.snippet
+				.expectPathParameters(
+						"present-optional-path-parameter")
+				.withContents(tableWithTitleAndHeader(
+						this.templateFormat == TemplateFormats.asciidoctor() ? "/{a}"
+								: "`/{a}`",
+						"Parameter", "Description").row("a", "one"));
+		new PathParametersSnippet(
+				Arrays.asList(parameterWithName("a").description("one").optional()))
+						.document(operationBuilder("present-optional-path-parameter")
+								.attribute(
+										RestDocumentationGenerator.ATTRIBUTE_NAME_URL_TEMPLATE,
+										"/{a}")
+								.build());
+	}
+
 	@Test
 	public void pathParametersWithQueryString() throws IOException {
 		this.snippet.expectPathParameters("path-parameters-with-query-string")
diff --git a/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/RequestParametersSnippetTests.java b/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/RequestParametersSnippetTests.java
index 380f1cc3..2bd69444 100644
--- a/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/RequestParametersSnippetTests.java
+++ b/spring-restdocs-core/src/test/java/org/springframework/restdocs/request/RequestParametersSnippetTests.java
@@ -104,6 +104,17 @@ public class RequestParametersSnippetTests extends AbstractSnippetTests {
 										.build());
 	}
 
+	@Test
+	public void presentOptionalRequestParameter() throws IOException {
+		this.snippet.expectRequestParameters("present-optional-request-parameter")
+				.withContents(
+						tableWithHeader("Parameter", "Description").row("a", "one"));
+		new RequestParametersSnippet(
+				Arrays.asList(parameterWithName("a").description("one").optional()))
+						.document(operationBuilder("present-optional-request-parameter")
+								.request("http://localhost").param("a", "one").build());
+	}
+
 	@Test
 	public void requestParametersWithCustomAttributes() throws IOException {
 		TemplateResourceResolver resolver = mock(TemplateResourceResolver.class);