diff --git a/conf/distro/include/java.inc b/conf/distro/include/java.inc
index 1e8ed3ff88e3fa086e87958cff3cff3641e9279b..2aafb6ab9fd3fd0a6eaed56eb4a8abede3798c0a 100644
--- a/conf/distro/include/java.inc
+++ b/conf/distro/include/java.inc
@@ -4,5 +4,5 @@
 
 # Configuration needed by meta-java layer
 
-PREFERRED_PROVIDER_virtual/java-initial-native = "cacao-initial-native"
-PREFERRED_PROVIDER_virtual/java-native = "cacao-native"
+PREFERRED_PROVIDER_virtual/java-initial-native ?= "cacao-initial-native"
+PREFERRED_PROVIDER_virtual/java-native ?= "cacao-native"