diff --git a/src/main/java/com/typesafe/config/impl/AbstractConfigObject.java b/src/main/java/com/typesafe/config/impl/AbstractConfigObject.java
index 9c351c39..06213e09 100644
--- a/src/main/java/com/typesafe/config/impl/AbstractConfigObject.java
+++ b/src/main/java/com/typesafe/config/impl/AbstractConfigObject.java
@@ -189,10 +189,10 @@ abstract class AbstractConfigObject extends AbstractConfigValue implements
 
     @Override
     public AbstractConfigObject withFallback(ConfigValue other) {
-        if (other instanceof Unresolved) {
+        if (other instanceof Unmergeable) {
             List<AbstractConfigValue> stack = new ArrayList<AbstractConfigValue>();
             stack.add(this);
-            stack.addAll(((Unresolved) other).unmergedValues());
+            stack.addAll(((Unmergeable) other).unmergedValues());
             return new ConfigDelayedMergeObject(mergeOrigins(stack), stack);
         } else if (other instanceof AbstractConfigObject) {
             AbstractConfigObject fallback = (AbstractConfigObject) other;
diff --git a/src/main/java/com/typesafe/config/impl/ConfigDelayedMerge.java b/src/main/java/com/typesafe/config/impl/ConfigDelayedMerge.java
index 04c48e8d..64b56beb 100644
--- a/src/main/java/com/typesafe/config/impl/ConfigDelayedMerge.java
+++ b/src/main/java/com/typesafe/config/impl/ConfigDelayedMerge.java
@@ -18,7 +18,7 @@ import com.typesafe.config.ConfigValueType;
  * substitutions.
  */
 final class ConfigDelayedMerge extends AbstractConfigValue implements
-        Unresolved {
+        Unmergeable {
 
     // earlier items in the stack win
     final private List<AbstractConfigValue> stack;
@@ -88,13 +88,13 @@ final class ConfigDelayedMerge extends AbstractConfigValue implements
     @Override
     public AbstractConfigValue withFallback(ConfigValue other) {
         if (other instanceof AbstractConfigObject
-                || other instanceof Unresolved) {
+                || other instanceof Unmergeable) {
             // if we turn out to be an object, and the fallback also does,
             // then a merge may be required; delay until we resolve.
             List<AbstractConfigValue> newStack = new ArrayList<AbstractConfigValue>();
             newStack.addAll(stack);
-            if (other instanceof Unresolved)
-                newStack.addAll(((Unresolved) other).unmergedValues());
+            if (other instanceof Unmergeable)
+                newStack.addAll(((Unmergeable) other).unmergedValues());
             else
                 newStack.add((AbstractConfigValue) other);
             return new ConfigDelayedMerge(
diff --git a/src/main/java/com/typesafe/config/impl/ConfigDelayedMergeObject.java b/src/main/java/com/typesafe/config/impl/ConfigDelayedMergeObject.java
index b3d98fd6..3e355fbf 100644
--- a/src/main/java/com/typesafe/config/impl/ConfigDelayedMergeObject.java
+++ b/src/main/java/com/typesafe/config/impl/ConfigDelayedMergeObject.java
@@ -14,7 +14,7 @@ import com.typesafe.config.ConfigValue;
 // This is just like ConfigDelayedMerge except we know statically
 // that it will turn out to be an object.
 class ConfigDelayedMergeObject extends AbstractConfigObject implements
-        Unresolved {
+        Unmergeable {
 
     final private List<AbstractConfigValue> stack;
 
@@ -85,13 +85,13 @@ class ConfigDelayedMergeObject extends AbstractConfigObject implements
     @Override
     public ConfigDelayedMergeObject withFallback(ConfigValue other) {
         if (other instanceof AbstractConfigObject
-                || other instanceof Unresolved) {
+                || other instanceof Unmergeable) {
             // since we are an object, and the fallback could be,
             // then a merge may be required; delay until we resolve.
             List<AbstractConfigValue> newStack = new ArrayList<AbstractConfigValue>();
             newStack.addAll(stack);
-            if (other instanceof Unresolved)
-                newStack.addAll(((Unresolved) other).unmergedValues());
+            if (other instanceof Unmergeable)
+                newStack.addAll(((Unmergeable) other).unmergedValues());
             else
                 newStack.add((AbstractConfigValue) other);
             return new ConfigDelayedMergeObject(
diff --git a/src/main/java/com/typesafe/config/impl/ConfigSubstitution.java b/src/main/java/com/typesafe/config/impl/ConfigSubstitution.java
index a70774a3..a1d74829 100644
--- a/src/main/java/com/typesafe/config/impl/ConfigSubstitution.java
+++ b/src/main/java/com/typesafe/config/impl/ConfigSubstitution.java
@@ -16,7 +16,7 @@ import com.typesafe.config.ConfigValueType;
  * than one piece it always resolves to a string via value concatenation.
  */
 final class ConfigSubstitution extends AbstractConfigValue implements
-        Unresolved {
+        Unmergeable {
 
     // this is a list of String and Path where the Path
     // have to be resolved to values, then if there's more
@@ -44,13 +44,13 @@ final class ConfigSubstitution extends AbstractConfigValue implements
     @Override
     public AbstractConfigValue withFallback(ConfigValue other) {
         if (other instanceof AbstractConfigObject
-                || other instanceof Unresolved) {
+                || other instanceof Unmergeable) {
             // if we turn out to be an object, and the fallback also does,
             // then a merge may be required; delay until we resolve.
             List<AbstractConfigValue> newStack = new ArrayList<AbstractConfigValue>();
             newStack.add(this);
-            if (other instanceof Unresolved)
-                newStack.addAll(((Unresolved) other).unmergedValues());
+            if (other instanceof Unmergeable)
+                newStack.addAll(((Unmergeable) other).unmergedValues());
             else
                 newStack.add((AbstractConfigValue) other);
             return new ConfigDelayedMerge(
diff --git a/src/main/java/com/typesafe/config/impl/Unmergeable.java b/src/main/java/com/typesafe/config/impl/Unmergeable.java
new file mode 100644
index 00000000..82dc203e
--- /dev/null
+++ b/src/main/java/com/typesafe/config/impl/Unmergeable.java
@@ -0,0 +1,13 @@
+package com.typesafe.config.impl;
+
+import java.util.Collection;
+
+/**
+ * Interface that tags a ConfigValue that is not mergeable until after
+ * substitutions are resolved. Basically these are special ConfigValue that
+ * never appear in a resolved tree, like {@link ConfigSubstitution} and
+ * {@link ConfigDelayedMerge}.
+ */
+interface Unmergeable {
+    Collection<? extends AbstractConfigValue> unmergedValues();
+}
diff --git a/src/main/java/com/typesafe/config/impl/Unresolved.java b/src/main/java/com/typesafe/config/impl/Unresolved.java
deleted file mode 100644
index 3bd1d1d4..00000000
--- a/src/main/java/com/typesafe/config/impl/Unresolved.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.typesafe.config.impl;
-
-import java.util.Collection;
-
-/**
- * Interface that tags a ConfigValue that is inherently not resolved; i.e. a
- * subclass of ConfigValue that will not appear in a resolved tree of values.
- * Types such as ConfigObject may not be resolved _yet_, but they are not
- * inherently unresolved.
- */
-interface Unresolved {
-    Collection<? extends AbstractConfigValue> unmergedValues();
-}