diff --git a/spring-test/src/main/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilder.java b/spring-test/src/main/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilder.java
index 8d688e7bfd4..a1b34f49a72 100644
--- a/spring-test/src/main/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilder.java
+++ b/spring-test/src/main/java/org/springframework/test/web/servlet/request/AbstractMockHttpServletRequestBuilder.java
@@ -342,7 +342,7 @@ public abstract class AbstractMockHttpServletRequestBuilder<B extends AbstractMo
 	 * @param values one or more header values
 	 */
 	public B header(String name, Object... values) {
-		addToMultiValueMap(this.headers, name, values);
+		this.headers.addAll(name, Arrays.asList(values));
 		return self();
 	}
 
@@ -372,11 +372,7 @@ public abstract class AbstractMockHttpServletRequestBuilder<B extends AbstractMo
 	 * @param values one or more values
 	 */
 	public B param(String name, String... values) {
-		if (values.length == 0) {
-			this.parameters.computeIfAbsent(name, k -> new ArrayList<>());
-			return self();
-		}
-		addToMultiValueMap(this.parameters, name, values);
+		this.parameters.addAll(name, Arrays.asList(values));
 		return self();
 	}
 
@@ -823,10 +819,9 @@ public abstract class AbstractMockHttpServletRequestBuilder<B extends AbstractMo
 		if (query != null) {
 			request.setQueryString(query);
 		}
-		addRequestParams(request, UriComponentsBuilder.fromUri(uri).build().getQueryParams());
 
-		this.parameters.forEach((name, values) ->
-				request.addParameter(name, values.toArray(new String[0])));
+		addRequestParams(request, UriComponentsBuilder.fromUri(uri).build().getQueryParams());
+		this.parameters.forEach((name, values) -> request.addParameter(name, values.toArray(new String[0])));
 
 		if (!this.formFields.isEmpty()) {
 			if (this.content != null && this.content.length > 0) {
@@ -993,19 +988,10 @@ public abstract class AbstractMockHttpServletRequestBuilder<B extends AbstractMo
 		return request;
 	}
 
-
 	private static void addToMap(Map<String, Object> map, String name, Object value) {
 		Assert.hasLength(name, "'name' must not be empty");
 		Assert.notNull(value, "'value' must not be null");
 		map.put(name, value);
 	}
 
-	private static <T> void addToMultiValueMap(MultiValueMap<String, T> map, String name, T[] values) {
-		Assert.hasLength(name, "'name' must not be empty");
-		Assert.notEmpty(values, "'values' must not be empty");
-		for (T value : values) {
-			map.add(name, value);
-		}
-	}
-
 }
diff --git a/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java b/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
index 6ba183d9aa4..9225771224b 100644
--- a/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java
@@ -230,7 +230,7 @@ class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	void requestParameterFromQuery() {
+	void requestParameterFromQueryString() {
 		this.builder = new MockHttpServletRequestBuilder(GET).uri("/?foo=bar&foo=baz");
 
 		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
@@ -241,7 +241,7 @@ class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	void requestParameterFromQueryList() {
+	void requestParameterFromQueryStringWithListValues() {
 		this.builder = new MockHttpServletRequestBuilder(GET).uri("/?foo[0]=bar&foo[1]=baz");
 
 		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
@@ -263,25 +263,6 @@ class MockHttpServletRequestBuilderTests {
 		assertThat(request.getQueryString()).isEqualTo("foo=bar&foo=baz");
 	}
 
-	@Test // gh-35210
-	void queryParameterWithoutValues() {
-		this.builder = new MockHttpServletRequestBuilder(GET).uri("/");
-		this.builder.queryParam("foo");
-		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
-
-		assertThat(request.getQueryString()).isEqualTo("foo");
-		assertThat(request.getParameterMap().get("foo")).containsExactly();
-	}
-
-	@Test
-	void queryParametersWithUriAndQueryParam() {
-		this.builder = new MockHttpServletRequestBuilder(GET).uri("/path?param1=value1");
-		this.builder.queryParam("param1", "value2");
-		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
-
-		assertThat(request.getParameterMap().get("param1")).containsExactly("value1", "value2");
-	}
-
 	@Test
 	void queryParameterMap() {
 		this.builder = new MockHttpServletRequestBuilder(GET).uri("/");
@@ -299,7 +280,7 @@ class MockHttpServletRequestBuilderTests {
 	}
 
 	@Test
-	void queryParameterList() {
+	void queryParameterWithListValues() {
 		this.builder = new MockHttpServletRequestBuilder(GET).uri("/");
 		this.builder.queryParam("foo[0]", "bar");
 		this.builder.queryParam("foo[1]", "baz");
@@ -311,6 +292,25 @@ class MockHttpServletRequestBuilderTests {
 		assertThat(request.getParameter("foo[1]")).isEqualTo("baz");
 	}
 
+	@Test // gh-35329
+	void queryParameterAndQueryString() {
+		this.builder = new MockHttpServletRequestBuilder(GET).uri("/path?param1=value1");
+		this.builder.queryParam("param1", "value2");
+		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
+
+		assertThat(request.getParameterMap().get("param1")).containsExactly("value1", "value2");
+	}
+
+	@Test // gh-35210
+	void queryParameterWithoutValues() {
+		this.builder = new MockHttpServletRequestBuilder(GET).uri("/");
+		this.builder.queryParam("foo");
+		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
+
+		assertThat(request.getQueryString()).isEqualTo("foo");
+		assertThat(request.getParameterMap().get("foo")).containsExactly();
+	}
+
 	@Test
 	void formField() {
 		this.builder = new MockHttpServletRequestBuilder(POST).uri("/");