diff --git a/checker/src/main/java/dev/cel/checker/BUILD.bazel b/checker/src/main/java/dev/cel/checker/BUILD.bazel
index d5832a4f..0053d906 100644
--- a/checker/src/main/java/dev/cel/checker/BUILD.bazel
+++ b/checker/src/main/java/dev/cel/checker/BUILD.bazel
@@ -73,6 +73,7 @@ java_library(
         "//common",
         "//common:compiler_common",
         "//common:options",
+        "//common/annotations",
         "//common/ast:expr_converter",
         "//common/internal:env_visitor",
         "//common/internal:errors",
diff --git a/checker/src/main/java/dev/cel/checker/CelCheckerLegacyImpl.java b/checker/src/main/java/dev/cel/checker/CelCheckerLegacyImpl.java
index 4ed263c1..950c919e 100644
--- a/checker/src/main/java/dev/cel/checker/CelCheckerLegacyImpl.java
+++ b/checker/src/main/java/dev/cel/checker/CelCheckerLegacyImpl.java
@@ -40,6 +40,7 @@
 import dev.cel.common.CelSourceLocation;
 import dev.cel.common.CelValidationResult;
 import dev.cel.common.CelVarDecl;
+import dev.cel.common.annotations.Internal;
 import dev.cel.common.ast.CelExprConverter;
 import dev.cel.common.internal.EnvVisitable;
 import dev.cel.common.internal.EnvVisitor;
@@ -57,8 +58,12 @@
 /**
  * {@code CelChecker} implementation which uses the original CEL-Java APIs to provide a simple,
  * consistent interface for type-checking.
+ *
+ * <p>CEL Library Internals. Do Not Use. Consumers should use {@code CelCompilerFactory} to
+ * instantiate a type-checker.
  */
 @Immutable
+@Internal
 public final class CelCheckerLegacyImpl implements CelChecker, EnvVisitable {
 
   private final CelOptions celOptions;