diff --git a/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java b/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
index 32e81c6f1f..869f9ca051 100644
--- a/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
+++ b/spring-core/src/main/java/org/springframework/util/xml/XmlValidationModeDetector.java
@@ -97,7 +97,7 @@ public class XmlValidationModeDetector {
 			String content;
 			while ((content = reader.readLine()) != null) {
 				content = consumeCommentTokens(content);
-				if (this.inComment || !StringUtils.hasText(content)) {
+				if (!StringUtils.hasText(content)) {
 					continue;
 				}
 				if (hasDoctype(content)) {
@@ -143,11 +143,10 @@ public class XmlValidationModeDetector {
 	}
 
 	/**
-	 * Consume all leading and trailing comments in the given String and return
-	 * the remaining content, which may be empty since the supplied content might
-	 * be all comment data.
+	 * Consume all comments in the given String and return the remaining content,
+	 * which may be empty since the supplied content might be all comment data.
+	 * <p>This method takes the current "in comment" parsing state into account.
 	 */
-	@Nullable
 	private String consumeCommentTokens(String line) {
 		int indexOfStartComment = line.indexOf(START_COMMENT);
 		if (indexOfStartComment == -1 && !line.contains(END_COMMENT)) {
@@ -156,17 +155,15 @@ public class XmlValidationModeDetector {
 
 		String result = "";
 		String currLine = line;
-		if (indexOfStartComment >= 0) {
+		if (!this.inComment && (indexOfStartComment >= 0)) {
 			result = line.substring(0, indexOfStartComment);
 			currLine = line.substring(indexOfStartComment);
 		}
 
-		while ((currLine = consume(currLine)) != null) {
-			if (!this.inComment && !currLine.trim().startsWith(START_COMMENT)) {
-				return result + currLine;
-			}
+		if ((currLine = consume(currLine)) != null) {
+			result += consumeCommentTokens(currLine);
 		}
-		return null;
+		return result;
 	}
 
 	/**
diff --git a/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java b/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
index 5951d29830..35a5e13222 100644
--- a/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
+++ b/spring-core/src/test/java/org/springframework/util/xml/XmlValidationModeDetectorTests.java
@@ -24,6 +24,7 @@ import org.junit.jupiter.params.provider.ValueSource;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.util.xml.XmlValidationModeDetector.VALIDATION_DTD;
+import static org.springframework.util.xml.XmlValidationModeDetector.VALIDATION_XSD;
 
 /**
  * Unit tests for {@link XmlValidationModeDetector}.
@@ -37,12 +38,29 @@ class XmlValidationModeDetectorTests {
 
 
 	@ParameterizedTest
-	@ValueSource(strings = { "dtdWithTrailingComment.xml", "dtdWithLeadingComment.xml", "dtdWithCommentOnNextLine.xml",
-		"dtdWithMultipleComments.xml" })
+	@ValueSource(strings = {
+		"dtdWithNoComments.xml",
+		"dtdWithLeadingComment.xml",
+		"dtdWithTrailingComment.xml",
+		"dtdWithTrailingCommentAcrossMultipleLines.xml",
+		"dtdWithCommentOnNextLine.xml",
+		"dtdWithMultipleComments.xml"
+	})
 	void dtdDetection(String fileName) throws Exception {
 		assertValidationMode(fileName, VALIDATION_DTD);
 	}
 
+	@ParameterizedTest
+	@ValueSource(strings = {
+		"xsdWithNoComments.xml",
+		"xsdWithMultipleComments.xml",
+		"xsdWithDoctypeInComment.xml",
+		"xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml"
+	})
+	void xsdDetection(String fileName) throws Exception {
+		assertValidationMode(fileName, VALIDATION_XSD);
+	}
+
 
 	private void assertValidationMode(String fileName, int expectedValidationMode) throws IOException {
 		try (InputStream inputStream = getClass().getResourceAsStream(fileName)) {
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/dtdWithNoComments.xml b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithNoComments.xml
new file mode 100644
index 0000000000..299c52abef
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithNoComments.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "https://www.springframework.org/dtd/spring-beans-2.0.dtd">
+
+<beans>
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/dtdWithTrailingCommentAcrossMultipleLines.xml b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithTrailingCommentAcrossMultipleLines.xml
new file mode 100644
index 0000000000..68776b4f61
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/dtdWithTrailingCommentAcrossMultipleLines.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "https://www.springframework.org/dtd/spring-beans-2.0.dtd"><!-- comment --><beans><!--
+trailing comment across multiple lines -->
+
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInComment.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInComment.xml
new file mode 100644
index 0000000000..3f0fd05ed9
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInComment.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "https://www.springframework.org/dtd/spring-beans-2.0.dtd"> -->
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd">
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml
new file mode 100644
index 0000000000..3d831932a9
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithDoctypeInOpenCommentWithAdditionalCommentOnSameLine.xml
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "https://www.springframework.org/dtd/spring-beans-2.0.dtd"> -->    <!-- additional comment on same line -->
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd">
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleComments.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleComments.xml
new file mode 100644
index 0000000000..8843539e4a
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithMultipleComments.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- comment #1 -->  <!-- comment #2 -->  <beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd"><!--
+trailing  
+      comment
+-->
+
+</beans>
diff --git a/spring-core/src/test/resources/org/springframework/util/xml/xsdWithNoComments.xml b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithNoComments.xml
new file mode 100644
index 0000000000..4f178c702f
--- /dev/null
+++ b/spring-core/src/test/resources/org/springframework/util/xml/xsdWithNoComments.xml
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<beans xmlns="http://www.springframework.org/schema/beans"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="https://www.springframework.org/schema/beans
+		https://www.springframework.org/schema/beans/spring-beans.xsd">
+
+</beans>