diff --git a/src/main/java/com/google/devtools/build/lib/actions/AbstractAction.java b/src/main/java/com/google/devtools/build/lib/actions/AbstractAction.java
index 0b272fb..c241c56 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/AbstractAction.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/AbstractAction.java
@@ -428,10 +428,13 @@
     for (Artifact input : getMandatoryInputs()) {
       // Assume that if the file did not exist, we would not have gotten here.
       try {
-        if (input.isSourceArtifact() && !metadataProvider.getMetadata(input).isFile()) {
-          eventHandler.handle(Event.warn(getOwner().getLocation(), "input '"
-              + input.prettyPrint() + "' to " + getOwner().getLabel()
-              + " is a directory; dependency checking of directories is unsound"));
+        if (input.isSourceArtifact()
+            && metadataProvider.getMetadata(input).getType().isDirectory()) {
+          // TODO(ulfjack): What about dependency checking of special files?
+          eventHandler.handle(Event.warn(getOwner().getLocation(),
+              String.format(
+                  "input '%s' to %s is a directory; dependency checking of directories is unsound",
+                  input.prettyPrint(), getOwner().getLabel())));
         }
       } catch (IOException e) {
         throw new UserExecException(e);
diff --git a/src/main/java/com/google/devtools/build/lib/actions/ActionCacheChecker.java b/src/main/java/com/google/devtools/build/lib/actions/ActionCacheChecker.java
index 8e4dc88..b6957cf 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/ActionCacheChecker.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/ActionCacheChecker.java
@@ -51,15 +51,21 @@
  * otherwise lightweight, and should be constructed anew and discarded for each build request.
  */
 public class ActionCacheChecker {
+  private static final byte[] EMPTY_DIGEST = new byte[0];
   private static final Metadata CONSTANT_METADATA = new Metadata() {
     @Override
+    public FileStateType getType() {
+      return FileStateType.REGULAR_FILE;
+    }
+
+    @Override
     public boolean isFile() {
-      return false;
+      return true;
     }
 
     @Override
     public byte[] getDigest() {
-      throw new UnsupportedOperationException();
+      return EMPTY_DIGEST;
     }
 
     @Override
diff --git a/src/main/java/com/google/devtools/build/lib/actions/FileStateType.java b/src/main/java/com/google/devtools/build/lib/actions/FileStateType.java
new file mode 100644
index 0000000..8e339e4
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/actions/FileStateType.java
@@ -0,0 +1,79 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.actions;
+
+/** An enum indicating the type of a path on the file system. */
+public enum FileStateType {
+  REGULAR_FILE("file"),
+  /**
+   * A special file such as a socket, fifo, or device. See
+   * {@link com.google.devtools.build.lib.vfs.FileStatus#isSpecialFile}.
+   */
+  SPECIAL_FILE("special file"),
+  DIRECTORY("directory"),
+  SYMLINK("symlink"),
+  NONEXISTENT("non-existent path");
+
+  private final String name;
+
+  private FileStateType(String name) {
+    this.name = name;
+  }
+
+  public String getHumanReadableName() {
+    return name;
+  }
+
+  /** Returns true if this type does not correspond to a non-existent path. */
+  public boolean exists() {
+    return this != NONEXISTENT;
+  }
+
+  /** Returns true if this value corresponds to a symlink. */
+  public boolean isSymlink() {
+    return this == SYMLINK;
+  }
+
+  /**
+   * Returns true if this value corresponds to a regular file. If so, its parent directory is
+   * guaranteed to exist.
+   */
+  public boolean isFile() {
+    return this == REGULAR_FILE;
+  }
+
+  /**
+   * Returns true if this value corresponds to a special file. If so, its parent directory is
+   * guaranteed to exist.
+   */
+  public boolean isSpecialFile() {
+    return this == SPECIAL_FILE;
+  }
+
+  /**
+   * Returns true if this value corresponds to a regular or special file. If so, its parent
+   * directory is guaranteed to exist.
+   */
+  public boolean isRegularOrSpecialFile() {
+    return this == REGULAR_FILE || this == FileStateType.SPECIAL_FILE;
+  }
+
+  /**
+   * Returns true if the file is a directory. If so, its parent directory is guaranteed to exist.
+   */
+  public boolean isDirectory() {
+    return this == DIRECTORY;
+  }
+}
\ No newline at end of file
diff --git a/src/main/java/com/google/devtools/build/lib/actions/MetadataProvider.java b/src/main/java/com/google/devtools/build/lib/actions/MetadataProvider.java
index 40d54b6..1538286 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/MetadataProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/MetadataProvider.java
@@ -29,6 +29,10 @@
    * then t >= p. Aside from these properties, t can be any value and may vary arbitrarily across
    * calls.
    *
+   * <p>Returned {@link Metadata} instance correspond to the final target of a symlink, and
+   * therefore must not have a type of
+   * {@link com.google.devtools.build.lib.actions.FileStateType#SYMLINK} themselves.
+   *
    * The return value is owned by the cache and must not be modified.
    *
    * @param input the input to retrieve the digest for
diff --git a/src/main/java/com/google/devtools/build/lib/actions/cache/Metadata.java b/src/main/java/com/google/devtools/build/lib/actions/cache/Metadata.java
index 642bd29..c14cb03 100644
--- a/src/main/java/com/google/devtools/build/lib/actions/cache/Metadata.java
+++ b/src/main/java/com/google/devtools/build/lib/actions/cache/Metadata.java
@@ -14,12 +14,12 @@
 
 package com.google.devtools.build.lib.actions.cache;
 
+import com.google.devtools.build.lib.actions.FileStateType;
+
 /**
- * An interface to represent the state of a file (or directory). This is used to determine whether a
- * file has changed or not.
- *
- * <p>NB! Several other parts of Blaze are relying on the fact that metadata uses mtime and not
- * ctime. If metadata is ever changed to use ctime, all uses of Metadata must be carefully examined.
+ * An interface to represent the state of a file system object for the execution phase. This is not
+ * used by Skyframe for invalidation, it is primarily used by the action cache and the various
+ * {@link com.google.devtools.build.lib.exec.SpawnRunner} implementations.
  */
 public interface Metadata {
   /**
@@ -30,6 +30,14 @@
   }
 
   /**
+   * The type of the underlying file system object. If it is a regular file, then it is
+   * guaranteed to have a digest. Otherwise it does not have a digest.
+   */
+  default FileStateType getType() {
+    return isFile() ? FileStateType.REGULAR_FILE : FileStateType.DIRECTORY;
+  }
+
+  /**
    * Whether the underlying file system object is a file or a symlink to a file, rather than a
    * directory. All files are guaranteed to have a digest, and {@link #getDigest} must only be
    * called on files.
@@ -40,7 +48,7 @@
    * Returns the file's digest; must only be called on objects for which {@link #isFile} returns
    * true.
    *
-   * <p>The return value is owned by the cache and must not be modified.
+   * <p>The return value is owned by this object and must not be modified.
    */
   byte[] getDigest();
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ActionMetadataHandler.java b/src/main/java/com/google/devtools/build/lib/skyframe/ActionMetadataHandler.java
index 2a8c6e5..4e087db 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ActionMetadataHandler.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ActionMetadataHandler.java
@@ -219,7 +219,7 @@
     }
     // We do not cache exceptions besides nonexistence here, because it is unlikely that the file
     // will be requested from this cache too many times.
-    fileValue = constructFileValue(artifact, null);
+    fileValue = constructFileValue(artifact, /*statNoFollow=*/ null);
     return maybeStoreAdditionalData(artifact, fileValue, null);
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java
index 7f45e7d..6bc9f5a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/FileArtifactValue.java
@@ -17,6 +17,7 @@
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
 import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.actions.FileStateType;
 import com.google.devtools.build.lib.actions.cache.DigestUtils;
 import com.google.devtools.build.lib.actions.cache.Metadata;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
@@ -45,6 +46,11 @@
 @Immutable @ThreadSafe
 public abstract class FileArtifactValue implements SkyValue, Metadata {
   private static final class SingletonMarkerValue extends FileArtifactValue implements Singleton {
+    @Override
+    public FileStateType getType() {
+      return FileStateType.NONEXISTENT;
+    }
+
     @Nullable
     @Override
     public byte[] getDigest() {
@@ -74,6 +80,11 @@
 
   private static final class OmittedFileValue extends FileArtifactValue implements Singleton {
     @Override
+    public FileStateType getType() {
+      return FileStateType.NONEXISTENT;
+    }
+
+    @Override
     public byte[] getDigest() {
       throw new UnsupportedOperationException();
     }
@@ -117,6 +128,11 @@
       this.mtime = mtime;
     }
 
+    @Override
+    public FileStateType getType() {
+      return FileStateType.DIRECTORY;
+    }
+
     @Nullable
     @Override
     public byte[] getDigest() {
@@ -154,6 +170,11 @@
     }
 
     @Override
+    public FileStateType getType() {
+      return FileStateType.REGULAR_FILE;
+    }
+
+    @Override
     public byte[] getDigest() {
       return digest;
     }
@@ -255,10 +276,13 @@
       return false;
     }
     Metadata m = (Metadata) o;
+    if (getType() != m.getType()) {
+      return false;
+    }
     if (isFile()) {
-      return m.isFile() && Arrays.equals(getDigest(), m.getDigest()) && getSize() == m.getSize();
+      return Arrays.equals(getDigest(), m.getDigest()) && getSize() == m.getSize();
     } else {
-      return !m.isFile() && getModifiedTime() == m.getModifiedTime();
+      return getModifiedTime() == m.getModifiedTime();
     }
   }
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/FileFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/FileFunction.java
index acac707..965c4c5 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/FileFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/FileFunction.java
@@ -18,8 +18,8 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Sets;
+import com.google.devtools.build.lib.actions.FileStateType;
 import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
-import com.google.devtools.build.lib.skyframe.FileStateValue.Type;
 import com.google.devtools.build.lib.util.Pair;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.PathFragment;
@@ -69,7 +69,7 @@
       }
       realRootedPath = resolvedState.getFirst();
       realFileStateValue = resolvedState.getSecond();
-      if (realFileStateValue.getType() == Type.NONEXISTENT) {
+      if (realFileStateValue.getType() == FileStateType.NONEXISTENT) {
         return FileValue.value(
             rootedPath,
             FileStateValue.NONEXISTENT_FILE_STATE_NODE,
@@ -95,7 +95,7 @@
 
     ArrayList<RootedPath> symlinkChain = new ArrayList<>();
     TreeSet<Path> orderedSeenPaths = Sets.newTreeSet();
-    while (realFileStateValue.getType().equals(FileStateValue.Type.SYMLINK)) {
+    while (realFileStateValue.getType().isSymlink()) {
       symlinkChain.add(realRootedPath);
       orderedSeenPaths.add(realRootedPath.asPath());
       Pair<RootedPath, FileStateValue> resolvedState = getSymlinkTargetRootedPath(realRootedPath,
@@ -145,7 +145,7 @@
     if (realFileStateValue == null) {
       return null;
     }
-    if (realFileStateValue.getType() != FileStateValue.Type.NONEXISTENT
+    if (realFileStateValue.getType() != FileStateType.NONEXISTENT
         && parentFileValue != null && !parentFileValue.isDirectory()) {
       String type = realFileStateValue.getType().toString().toLowerCase();
       String message = type + " " + rootedPath.asPath() + " exists but its parent "
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/FileStateValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/FileStateValue.java
index c309b42..2595663 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/FileStateValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/FileStateValue.java
@@ -14,7 +14,9 @@
 package com.google.devtools.build.lib.skyframe;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.MoreObjects;
 import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.actions.FileStateType;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
 import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
 import com.google.devtools.build.lib.vfs.FileStatus;
@@ -33,10 +35,10 @@
 import javax.annotation.Nullable;
 
 /**
- * Encapsulates the filesystem operations needed to get state for a path. This is at least a
- * 'lstat' to determine what type of file the path is.
+ * Encapsulates the filesystem operations needed to get state for a path. This is equivalent to an
+ * 'lstat' that does not follow symlinks to determine what type of file the path is.
  * <ul>
- *   <li> For a non-existent file, the non existence is noted.
+ *   <li> For a non-existent file, the non-existence is noted.
  *   <li> For a symlink, the symlink target is noted.
  *   <li> For a directory, the existence is noted.
  *   <li> For a file, the existence is noted, along with metadata about the file (e.g.
@@ -58,15 +60,6 @@
   public static final NonexistentFileStateValue NONEXISTENT_FILE_STATE_NODE =
       new NonexistentFileStateValue();
 
-  /** Type of a path. */
-  public enum Type {
-    REGULAR_FILE,
-    SPECIAL_FILE,
-    DIRECTORY,
-    SYMLINK,
-    NONEXISTENT,
-  }
-
   protected FileStateValue() {
   }
 
@@ -106,8 +99,9 @@
     return LegacySkyKey.create(SkyFunctions.FILE_STATE, rootedPath);
   }
 
-  public abstract Type getType();
+  public abstract FileStateType getType();
 
+  /** Returns the target of the symlink, or throws an exception if this is not a symlink. */
   PathFragment getSymlinkTarget() {
     throw new IllegalStateException();
   }
@@ -205,8 +199,8 @@
     }
 
     @Override
-    public Type getType() {
-      return Type.REGULAR_FILE;
+    public FileStateType getType() {
+      return FileStateType.REGULAR_FILE;
     }
 
     @Override
@@ -230,12 +224,17 @@
 
     @Override
     public boolean equals(Object obj) {
-      if (obj instanceof RegularFileStateValue) {
-        RegularFileStateValue other = (RegularFileStateValue) obj;
-        return size == other.size && mtime == other.mtime && Arrays.equals(digest, other.digest)
-            && Objects.equals(contentsProxy, other.contentsProxy);
+      if (obj == this) {
+        return true;
       }
-      return false;
+      if (!(obj instanceof RegularFileStateValue)) {
+        return false;
+      }
+      RegularFileStateValue other = (RegularFileStateValue) obj;
+      return size == other.size
+          && mtime == other.mtime
+          && Arrays.equals(digest, other.digest)
+          && Objects.equals(contentsProxy, other.contentsProxy);
     }
 
     @Override
@@ -244,6 +243,15 @@
     }
 
     @Override
+    public String toString() {
+      return MoreObjects.toStringHelper(this)
+          .add("digest", digest)
+          .add("size", size)
+          .add("mtime", mtime)
+          .add("contentsProxy", contentsProxy).toString();
+    }
+
+    @Override
     public String prettyPrint() {
       String contents = digest != null
           ? String.format("digest of %s", Arrays.toString(digest))
@@ -261,11 +269,10 @@
       this.contentsProxy = contentsProxy;
     }
 
-    static SpecialFileStateValue fromStat(PathFragment path, FileStatusWithDigest stat,
+    static SpecialFileStateValue fromStat(PathFragment path, FileStatus stat,
         @Nullable TimestampGranularityMonitor tsgm) throws IOException {
       long mtime = stat.getLastModifiedTime();
-      // Note that TimestampGranularityMonitor#notifyDependenceOnFileTime is a thread-safe
-      // method.
+      // Note that TimestampGranularityMonitor#notifyDependenceOnFileTime is a thread-safe method.
       if (tsgm != null) {
         tsgm.notifyDependenceOnFileTime(path, mtime);
       }
@@ -273,8 +280,8 @@
     }
 
     @Override
-    public Type getType() {
-      return Type.SPECIAL_FILE;
+    public FileStateType getType() {
+      return FileStateType.SPECIAL_FILE;
     }
 
     @Override
@@ -294,11 +301,14 @@
 
     @Override
     public boolean equals(Object obj) {
-      if (obj instanceof SpecialFileStateValue) {
-        SpecialFileStateValue other = (SpecialFileStateValue) obj;
-        return Objects.equals(contentsProxy, other.contentsProxy);
+      if (obj == this) {
+        return true;
       }
-      return false;
+      if (!(obj instanceof SpecialFileStateValue)) {
+        return false;
+      }
+      SpecialFileStateValue other = (SpecialFileStateValue) obj;
+      return Objects.equals(contentsProxy, other.contentsProxy);
     }
 
     @Override
@@ -319,8 +329,8 @@
     }
 
     @Override
-    public Type getType() {
-      return Type.DIRECTORY;
+    public FileStateType getType() {
+      return FileStateType.DIRECTORY;
     }
 
     @Override
@@ -350,8 +360,8 @@
     }
 
     @Override
-    public Type getType() {
-      return Type.SYMLINK;
+    public FileStateType getType() {
+      return FileStateType.SYMLINK;
     }
 
     @Override
@@ -386,8 +396,8 @@
     }
 
     @Override
-    public Type getType() {
-      return Type.NONEXISTENT;
+    public FileStateType getType() {
+      return FileStateType.NONEXISTENT;
     }
 
     @Override
@@ -398,6 +408,9 @@
     // This object is normally a singleton, but deserialization produces copies.
     @Override
     public boolean equals(Object obj) {
+      if (obj == this) {
+        return true;
+      }
       return obj instanceof NonexistentFileStateValue;
     }
 
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/FileValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/FileValue.java
index 441bf69..7374bf3 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/FileValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/FileValue.java
@@ -14,9 +14,9 @@
 package com.google.devtools.build.lib.skyframe;
 
 import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.actions.FileStateType;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
 import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
-import com.google.devtools.build.lib.skyframe.FileStateValue.Type;
 import com.google.devtools.build.lib.vfs.PathFragment;
 import com.google.devtools.build.lib.vfs.RootedPath;
 import com.google.devtools.build.skyframe.LegacySkyKey;
@@ -48,9 +48,10 @@
 public abstract class FileValue implements SkyValue {
 
   public boolean exists() {
-    return realFileStateValue().getType() != Type.NONEXISTENT;
+    return realFileStateValue().getType() != FileStateType.NONEXISTENT;
   }
 
+  /** Returns true if the original path is a symlink; the target path can never be a symlink. */
   public boolean isSymlink() {
     return false;
   }
@@ -60,8 +61,8 @@
    * file. If so, its parent directory is guaranteed to exist.
    */
   public boolean isFile() {
-    return realFileStateValue().getType() == Type.REGULAR_FILE
-        || realFileStateValue().getType() == Type.SPECIAL_FILE;
+    return realFileStateValue().getType() == FileStateType.REGULAR_FILE
+        || realFileStateValue().getType() == FileStateType.SPECIAL_FILE;
   }
 
   /**
@@ -69,7 +70,7 @@
    * its parent directory is guaranteed to exist.
    */
   public boolean isSpecialFile() {
-    return realFileStateValue().getType() == Type.SPECIAL_FILE;
+    return realFileStateValue().getType() == FileStateType.SPECIAL_FILE;
   }
 
   /**
@@ -77,7 +78,7 @@
    * parent directory is guaranteed to exist.
    */
   public boolean isDirectory() {
-    return realFileStateValue().getType() == Type.DIRECTORY;
+    return realFileStateValue().getType() == FileStateType.DIRECTORY;
   }
 
   /**
@@ -125,12 +126,12 @@
   static FileValue value(RootedPath rootedPath, FileStateValue fileStateValue,
                          RootedPath realRootedPath, FileStateValue realFileStateValue) {
     if (rootedPath.equals(realRootedPath)) {
-      Preconditions.checkState(fileStateValue.getType() != FileStateValue.Type.SYMLINK,
+      Preconditions.checkState(fileStateValue.getType() != FileStateType.SYMLINK,
           "rootedPath: %s, fileStateValue: %s, realRootedPath: %s, realFileStateValue: %s",
           rootedPath, fileStateValue, realRootedPath, realFileStateValue);
       return new RegularFileValue(rootedPath, fileStateValue);
     } else {
-      if (fileStateValue.getType() == FileStateValue.Type.SYMLINK) {
+      if (fileStateValue.getType() == FileStateType.SYMLINK) {
         return new SymlinkFileValue(realRootedPath, realFileStateValue,
             fileStateValue.getSymlinkTarget());
       } else {
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
index 3c450d3..5924481 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/SkyframeExecutor.java
@@ -50,6 +50,7 @@
 import com.google.devtools.build.lib.actions.ArtifactOwner;
 import com.google.devtools.build.lib.actions.EnvironmentalExecException;
 import com.google.devtools.build.lib.actions.Executor;
+import com.google.devtools.build.lib.actions.FileStateType;
 import com.google.devtools.build.lib.actions.ResourceManager;
 import com.google.devtools.build.lib.actions.Root;
 import com.google.devtools.build.lib.analysis.AspectCollection;
@@ -911,12 +912,11 @@
 
   protected abstract void invalidate(Predicate<SkyKey> pred);
 
-  private static boolean compatibleFileTypes(Dirent.Type oldType, FileStateValue.Type newType) {
-    return (oldType.equals(Dirent.Type.FILE) && newType.equals(FileStateValue.Type.REGULAR_FILE))
-        || (oldType.equals(Dirent.Type.UNKNOWN)
-            && newType.equals(FileStateValue.Type.SPECIAL_FILE))
-        || (oldType.equals(Dirent.Type.DIRECTORY) && newType.equals(FileStateValue.Type.DIRECTORY))
-        || (oldType.equals(Dirent.Type.SYMLINK) && newType.equals(FileStateValue.Type.SYMLINK));
+  private static boolean compatibleFileTypes(Dirent.Type oldType, FileStateType newType) {
+    return (oldType.equals(Dirent.Type.FILE) && newType.equals(FileStateType.REGULAR_FILE))
+        || (oldType.equals(Dirent.Type.UNKNOWN) && newType.equals(FileStateType.SPECIAL_FILE))
+        || (oldType.equals(Dirent.Type.DIRECTORY) && newType.equals(FileStateType.DIRECTORY))
+        || (oldType.equals(Dirent.Type.SYMLINK) && newType.equals(FileStateType.SYMLINK));
   }
 
   protected Differencer.Diff getDiff(TimestampGranularityMonitor tsgm,
diff --git a/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java b/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
index 5fc0f38..a39e47f 100644
--- a/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
+++ b/src/main/java/com/google/devtools/build/lib/worker/WorkerFilesHash.java
@@ -74,7 +74,7 @@
         Artifact localArtifact = mapping.getValue();
         if (localArtifact != null) {
           Metadata metadata = actionInputFileCache.getMetadata(localArtifact);
-          if (metadata.isFile()) {
+          if (metadata.getType().isFile()) {
             workerFilesMap.put(
                 root.getRelative(mapping.getKey()),
                 HashCode.fromBytes(metadata.getDigest()));