diff --git a/core/spring-boot/src/main/java/org/springframework/boot/logging/CorrelationIdFormatter.java b/core/spring-boot/src/main/java/org/springframework/boot/logging/CorrelationIdFormatter.java
index d7b7a7ea50e7..e1854e4cd8c7 100644
--- a/core/spring-boot/src/main/java/org/springframework/boot/logging/CorrelationIdFormatter.java
+++ b/core/spring-boot/src/main/java/org/springframework/boot/logging/CorrelationIdFormatter.java
@@ -87,7 +87,7 @@ private CorrelationIdFormatter(List<Part> parts) {
 	 * @return a formatted correlation id
 	 */
 	public String format(UnaryOperator<@Nullable String> resolver) {
-		StringBuilder result = new StringBuilder();
+		StringBuilder result = new StringBuilder(this.blank.length());
 		formatTo(resolver, result);
 		return result.toString();
 	}