diff --git a/common/src/main/java/dev/cel/common/internal/ProtoAdapter.java b/common/src/main/java/dev/cel/common/internal/ProtoAdapter.java
index 29fece49..28da7e5d 100644
--- a/common/src/main/java/dev/cel/common/internal/ProtoAdapter.java
+++ b/common/src/main/java/dev/cel/common/internal/ProtoAdapter.java
@@ -17,7 +17,6 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.ImmutableMap.toImmutableMap;
 
-import dev.cel.expr.ExprValue;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.primitives.Ints;
@@ -205,9 +204,6 @@ public Object adaptProtoToValue(MessageOrBuilder proto) {
 
   @SuppressWarnings({"unchecked", "rawtypes"})
   public Optional<Object> adaptFieldToValue(FieldDescriptor fieldDescriptor, Object fieldValue) {
-    if (isUnknown(fieldValue)) {
-      return Optional.of(fieldValue);
-    }
     if (fieldDescriptor.isMapField()) {
       Descriptor entryDescriptor = fieldDescriptor.getMessageType();
       FieldDescriptor keyFieldDescriptor = entryDescriptor.findFieldByNumber(1);
@@ -255,9 +251,6 @@ public Optional<Object> adaptValueToFieldType(
     if (isWrapperType(fieldDescriptor) && fieldValue.equals(NullValue.NULL_VALUE)) {
       return Optional.empty();
     }
-    if (isUnknown(fieldValue)) {
-      return Optional.of(fieldValue);
-    }
     if (fieldDescriptor.isMapField()) {
       Descriptor entryDescriptor = fieldDescriptor.getMessageType();
       FieldDescriptor keyDescriptor = entryDescriptor.findFieldByNumber(1);
@@ -590,11 +583,6 @@ private static boolean isWrapperType(FieldDescriptor fieldDescriptor) {
     return wellKnownProto != null && wellKnownProto.isWrapperType();
   }
 
-  private static boolean isUnknown(Object object) {
-    return object instanceof ExprValue
-        && ((ExprValue) object).getKindCase() == ExprValue.KindCase.UNKNOWN;
-  }
-
   private static int intCheckedCast(long value) {
     try {
       return Ints.checkedCast(value);