diff --git a/core/runtime/src/main/java/io/quarkus/runtime/util/StringUtil.java b/core/runtime/src/main/java/io/quarkus/runtime/util/StringUtil.java
index e3bb032289536..52e33c76b2d50 100644
--- a/core/runtime/src/main/java/io/quarkus/runtime/util/StringUtil.java
+++ b/core/runtime/src/main/java/io/quarkus/runtime/util/StringUtil.java
@@ -112,13 +112,13 @@ public String next() {
     }
 
     /**
-     * @deprecated Use {@link String#join} instead.
+     * Dropped for public usage, kept in place for usage by hyphenate method to avoid need for lambda
+     *
      * @param delim delimiter
      * @param it iterator
      * @return the joined string
      */
-    @Deprecated
-    public static String join(String delim, Iterator<String> it) {
+    private static String join(String delim, Iterator<String> it) {
         final StringBuilder b = new StringBuilder();
         if (it.hasNext()) {
             b.append(it.next());
diff --git a/extensions/spring-boot-properties/deployment/src/main/java/io/quarkus/spring/boot/properties/deployment/ConfigurationPropertiesMetadataBuildItem.java b/extensions/spring-boot-properties/deployment/src/main/java/io/quarkus/spring/boot/properties/deployment/ConfigurationPropertiesMetadataBuildItem.java
index a7c67705c86e4..4e1549f6be0ca 100644
--- a/extensions/spring-boot-properties/deployment/src/main/java/io/quarkus/spring/boot/properties/deployment/ConfigurationPropertiesMetadataBuildItem.java
+++ b/extensions/spring-boot-properties/deployment/src/main/java/io/quarkus/spring/boot/properties/deployment/ConfigurationPropertiesMetadataBuildItem.java
@@ -1,7 +1,6 @@
 package io.quarkus.spring.boot.properties.deployment;
 
 import static io.quarkus.runtime.util.StringUtil.camelHumpsIterator;
-import static io.quarkus.runtime.util.StringUtil.join;
 import static io.quarkus.runtime.util.StringUtil.lowerCase;
 import static io.quarkus.runtime.util.StringUtil.withoutSuffix;
 
@@ -67,11 +66,10 @@ private String sanitisePrefix(String prefix) {
         return prefix;
     }
 
-    @SuppressWarnings("deprecation")
     private String getPrefixFromClassName(DotName className) {
         String simpleName = className.isInner() ? className.local() : className.withoutPackagePrefix();
-        return join("-",
-                withoutSuffix(lowerCase(camelHumpsIterator(simpleName)), "config", "configuration",
+        return String.join("-",
+                (Iterable<String>) () -> withoutSuffix(lowerCase(camelHumpsIterator(simpleName)), "config", "configuration",
                         "properties", "props"));
     }