diff --git a/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java b/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
index 0e070c3c806c..13ad367026d1 100644
--- a/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
+++ b/spring-web/src/main/java/org/springframework/web/context/request/ServletWebRequest.java
@@ -233,10 +233,7 @@ else if (validateIfUnmodifiedSince(lastModifiedTimestamp)) {
 
 	private boolean validateIfMatch(@Nullable String eTag) {
 		Enumeration<String> ifMatchHeaders = getRequest().getHeaders(HttpHeaders.IF_MATCH);
-		if (SAFE_METHODS.contains(getRequest().getMethod())) {
-			return false;
-		}
-		if (!ifMatchHeaders.hasMoreElements()) {
+		if (SAFE_METHODS.contains(getRequest().getMethod()) || !ifMatchHeaders.hasMoreElements()) {
 			return false;
 		}
 		this.notModified = matchRequestedETags(ifMatchHeaders, eTag, false);
@@ -309,7 +306,7 @@ private boolean eTagWeakMatch(@Nullable String first, @Nullable String second) {
 		return first.equals(second);
 	}
 
-	private void updateResponseStateChanging(String eTag, long lastModifiedTimestamp) {
+	private void updateResponseStateChanging(@Nullable String eTag, long lastModifiedTimestamp) {
 		if (this.notModified && getResponse() != null) {
 			getResponse().setStatus(HttpStatus.PRECONDITION_FAILED.value());
 		}
@@ -330,20 +327,18 @@ private boolean validateIfUnmodifiedSince(long lastModifiedTimestamp) {
 		return true;
 	}
 
-	private boolean validateIfModifiedSince(long lastModifiedTimestamp) {
+	private void validateIfModifiedSince(long lastModifiedTimestamp) {
 		if (lastModifiedTimestamp < 0) {
-			return false;
+			return;
 		}
 		long ifModifiedSince = parseDateHeader(HttpHeaders.IF_MODIFIED_SINCE);
-		if (ifModifiedSince == -1) {
-			return false;
+		if (ifModifiedSince != -1) {
+			// We will perform this validation...
+			this.notModified = ifModifiedSince >= (lastModifiedTimestamp / 1000 * 1000);
 		}
-		// We will perform this validation...
-		this.notModified = ifModifiedSince >= (lastModifiedTimestamp / 1000 * 1000);
-		return true;
 	}
 
-	private void updateResponseIdempotent(String eTag, long lastModifiedTimestamp) {
+	private void updateResponseIdempotent(@Nullable String eTag, long lastModifiedTimestamp) {
 		if (getResponse() != null) {
 			boolean isHttpGetOrHead = SAFE_METHODS.contains(getRequest().getMethod());
 			if (this.notModified) {
@@ -354,7 +349,7 @@ private void updateResponseIdempotent(String eTag, long lastModifiedTimestamp) {
 		}
 	}
 
-	private void addCachingResponseHeaders(String eTag, long lastModifiedTimestamp) {
+	private void addCachingResponseHeaders(@Nullable String eTag, long lastModifiedTimestamp) {
 		if (SAFE_METHODS.contains(getRequest().getMethod())) {
 			if (lastModifiedTimestamp > 0 && parseDateValue(getResponse().getHeader(HttpHeaders.LAST_MODIFIED)) == -1) {
 				getResponse().setDateHeader(HttpHeaders.LAST_MODIFIED, lastModifiedTimestamp);
diff --git a/spring-web/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java b/spring-web/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
index 06b949f955e8..43b7462fb91f 100644
--- a/spring-web/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
+++ b/spring-web/src/main/java/org/springframework/web/server/adapter/DefaultServerWebExchange.java
@@ -346,7 +346,7 @@ private boolean eTagWeakMatch(@Nullable String first, @Nullable String second) {
 		return first.equals(second);
 	}
 
-	private void updateResponseStateChanging(String eTag, Instant lastModified) {
+	private void updateResponseStateChanging(@Nullable String eTag, Instant lastModified) {
 		if (this.notModified) {
 			getResponse().setStatusCode(HttpStatus.PRECONDITION_FAILED);
 		}
@@ -401,17 +401,15 @@ private boolean validateIfUnmodifiedSince(Instant lastModified) {
 		return true;
 	}
 
-	private boolean validateIfModifiedSince(Instant lastModified) {
+	private void validateIfModifiedSince(Instant lastModified) {
 		if (lastModified.isBefore(Instant.EPOCH)) {
-			return false;
+			return;
 		}
 		long ifModifiedSince = getRequestHeaders().getIfModifiedSince();
-		if (ifModifiedSince == -1) {
-			return false;
+		if (ifModifiedSince != -1) {
+			// We will perform this validation...
+			this.notModified = ChronoUnit.SECONDS.between(lastModified, Instant.ofEpochMilli(ifModifiedSince)) >= 0;
 		}
-		// We will perform this validation...
-		this.notModified = ChronoUnit.SECONDS.between(lastModified, Instant.ofEpochMilli(ifModifiedSince)) >= 0;
-		return true;
 	}
 
 	@Override