diff --git a/implementation/src/main/java/io/smallrye/config/ConfigMappingProvider.java b/implementation/src/main/java/io/smallrye/config/ConfigMappingProvider.java
index 697406470..d6018203c 100644
--- a/implementation/src/main/java/io/smallrye/config/ConfigMappingProvider.java
+++ b/implementation/src/main/java/io/smallrye/config/ConfigMappingProvider.java
@@ -596,11 +596,15 @@ public static Builder builder() {
         return new Builder();
     }
 
-    public KeyMap<String> getDefaultValues() {
+    KeyMap<String> getDefaultValues() {
         return defaultValues;
     }
 
-    public ConfigMappings mapConfiguration(SmallRyeConfig config) throws ConfigValidationException {
+    ConfigMappings mapConfiguration(SmallRyeConfig config) throws ConfigValidationException {
+        return mapConfiguration(config, new ConfigMappings());
+    }
+
+    ConfigMappings mapConfiguration(SmallRyeConfig config, ConfigMappings mappings) throws ConfigValidationException {
         if (roots.isEmpty()) {
             return new ConfigMappings(new HashMap<>());
         }
@@ -640,7 +644,9 @@ public ConfigMappings mapConfiguration(SmallRyeConfig config) throws ConfigValid
                     problems.toArray(ConfigValidationException.Problem.NO_PROBLEMS));
         }
         context.fillInOptionals();
-        return new ConfigMappings(context.getRootsMap());
+
+        mappings.registerConfigMappings(context.getRootsMap());
+        return mappings;
     }
 
     private boolean isPropertyInRoot(String propertyName) {
diff --git a/implementation/src/main/java/io/smallrye/config/ConfigMappings.java b/implementation/src/main/java/io/smallrye/config/ConfigMappings.java
index c25103d9d..42920f7db 100644
--- a/implementation/src/main/java/io/smallrye/config/ConfigMappings.java
+++ b/implementation/src/main/java/io/smallrye/config/ConfigMappings.java
@@ -5,12 +5,12 @@
 import java.util.HashMap;
 import java.util.Map;
 
-public final class ConfigMappings implements Serializable {
+final class ConfigMappings implements Serializable {
     private static final long serialVersionUID = -7790784345796818526L;
 
     private final Map<Class<?>, Map<String, ConfigMappingObject>> mappings;
 
-    public ConfigMappings() {
+    ConfigMappings() {
         this(new HashMap<>());
     }
 
@@ -22,11 +22,7 @@ void registerConfigMappings(Map<Class<?>, Map<String, ConfigMappingObject>> mapp
         this.mappings.putAll(mappings);
     }
 
-    public Map<Class<?>, Map<String, ConfigMappingObject>> getMappings() {
-        return mappings;
-    }
-
-    public <T> T getConfigMapping(Class<T> type, String prefix) {
+    <T> T getConfigMapping(Class<T> type, String prefix) {
         final ConfigMappingObject configMappingObject = mappings.getOrDefault(type, Collections.emptyMap()).get(prefix);
         if (configMappingObject == null) {
             throw ConfigMessages.msg.mappingNotFound(type.getName(), prefix);
diff --git a/implementation/src/main/java/io/smallrye/config/SmallRyeConfig.java b/implementation/src/main/java/io/smallrye/config/SmallRyeConfig.java
index 43ce67bbd..eeca7c1b8 100644
--- a/implementation/src/main/java/io/smallrye/config/SmallRyeConfig.java
+++ b/implementation/src/main/java/io/smallrye/config/SmallRyeConfig.java
@@ -56,11 +56,12 @@ public class SmallRyeConfig implements Config, Serializable {
     private final Map<Type, Converter<?>> converters;
     private final Map<Type, Converter<Optional<?>>> optionalConverters = new ConcurrentHashMap<>();
 
-    private final ConfigMappings mappings = new ConfigMappings();
+    private final ConfigMappings mappings;
 
-    SmallRyeConfig(SmallRyeConfigBuilder builder) {
+    SmallRyeConfig(SmallRyeConfigBuilder builder, ConfigMappings mappings) {
         this.configSources = new AtomicReference<>(new ConfigSources(buildConfigSources(builder), buildInterceptors(builder)));
         this.converters = buildConverters(builder);
+        this.mappings = mappings;
     }
 
     @Deprecated
@@ -69,6 +70,7 @@ protected SmallRyeConfig(List<ConfigSource> configSources, Map<Type, Converter<?
                 new ConfigSources(configSources, buildInterceptors(new SmallRyeConfigBuilder())));
         this.converters = new ConcurrentHashMap<>(Converters.ALL_CONVERTERS);
         this.converters.putAll(converters);
+        this.mappings = new ConfigMappings();
     }
 
     private List<ConfigSource> buildConfigSources(final SmallRyeConfigBuilder builder) {
@@ -202,11 +204,6 @@ public <T, C extends Collection<T>> Optional<C> getOptionalValues(String name, C
         return getOptionalValue(name, Converters.newCollectionConverter(converter, collectionFactory));
     }
 
-    @Experimental("TODO")
-    void registerMappings(Map<Class<?>, Map<String, ConfigMappingObject>> mappings) {
-        this.mappings.registerConfigMappings(mappings);
-    }
-
     @Experimental("TODO")
     public <T> T getConfigMapping(Class<T> type) {
         return getConfigMapping(type, "");
diff --git a/implementation/src/main/java/io/smallrye/config/SmallRyeConfigBuilder.java b/implementation/src/main/java/io/smallrye/config/SmallRyeConfigBuilder.java
index 25d94a703..e14c9b49e 100644
--- a/implementation/src/main/java/io/smallrye/config/SmallRyeConfigBuilder.java
+++ b/implementation/src/main/java/io/smallrye/config/SmallRyeConfigBuilder.java
@@ -329,7 +329,7 @@ boolean isAddDiscoveredInterceptors() {
 
     @Override
     public SmallRyeConfig build() {
-        final ConfigMappingProvider mappingProvider = mappingsBuilder.build();
+        ConfigMappingProvider mappingProvider = mappingsBuilder.build();
         if (!defaultValues.isEmpty() || !mappingProvider.getDefaultValues().isEmpty()) {
             final KeyMap<String> mappingProviderDefaultValues = mappingProvider.getDefaultValues();
             defaultValues.forEach((key, value) -> mappingProviderDefaultValues.findOrAdd(key).putRootValue(value));
@@ -348,11 +348,10 @@ public int getOrdinal() {
             });
         }
 
-        final SmallRyeConfig config = new SmallRyeConfig(this);
-
         try {
-            final ConfigMappings result = mappingProvider.mapConfiguration(config);
-            config.registerMappings(result.getMappings());
+            ConfigMappings configMappings = new ConfigMappings();
+            SmallRyeConfig config = new SmallRyeConfig(this, configMappings);
+            mappingProvider.mapConfiguration(config, configMappings);
             return config;
         } catch (ConfigValidationException e) {
             throw new IllegalStateException(e);