diff --git a/src/com/facebook/buck/jvm/java/ExternalJavac.java b/src/com/facebook/buck/jvm/java/ExternalJavac.java
index 47f6f864f06..3e637956f57 100644
--- a/src/com/facebook/buck/jvm/java/ExternalJavac.java
+++ b/src/com/facebook/buck/jvm/java/ExternalJavac.java
@@ -58,14 +58,12 @@
 /** javac implemented in a separate binary. */
 public class ExternalJavac implements Javac {
   @AddToRuleKey private final Supplier<Tool> javac;
-  private final Either<PathSourcePath, BuildTargetSourcePath> actualPath;
   private final String shortName;
 
   public ExternalJavac(final Either<PathSourcePath, SourcePath> pathToJavac) {
     if (pathToJavac.isRight() && pathToJavac.getRight() instanceof BuildTargetSourcePath) {
       BuildTargetSourcePath buildTargetPath = (BuildTargetSourcePath) pathToJavac.getRight();
       this.shortName = buildTargetPath.getTarget().toString();
-      this.actualPath = Either.ofRight(buildTargetPath);
       this.javac =
           MoreSuppliers.memoize(
               () ->
@@ -89,7 +87,6 @@ public ImmutableMap<String, String> getEnvironment(
     } else {
       PathSourcePath actualPath =
           pathToJavac.transform(path -> path, path -> (PathSourcePath) path);
-      this.actualPath = Either.ofLeft(actualPath);
       this.shortName = actualPath.toString();
       this.javac =
           MoreSuppliers.memoize(
@@ -117,11 +114,6 @@ public ImmutableMap<String, String> getEnvironment(
     }
   }
 
-  @VisibleForTesting
-  Either<PathSourcePath, BuildTargetSourcePath> getActualPath() {
-    return actualPath;
-  }
-
   @Override
   public ImmutableList<String> getCommandPrefix(SourcePathResolver resolver) {
     return javac.get().getCommandPrefix(resolver);
@@ -198,9 +190,7 @@ public int buildClasses() throws InterruptedException {
             abiGenerationMode == AbiGenerationMode.CLASS,
             "Cannot compile ABI jars with external javac");
         ImmutableList.Builder<String> command = ImmutableList.builder();
-        command.add(
-            actualPath.transform(
-                Object::toString, path -> sourcePathResolver.getAbsolutePath(path).toString()));
+        command.addAll(javac.get().getCommandPrefix(sourcePathResolver));
         ImmutableList<Path> expandedSources;
         try {
           expandedSources =
diff --git a/test/com/facebook/buck/jvm/java/JavacSpecTest.java b/test/com/facebook/buck/jvm/java/JavacSpecTest.java
index 72485c41cd1..dd2cf466fbe 100644
--- a/test/com/facebook/buck/jvm/java/JavacSpecTest.java
+++ b/test/com/facebook/buck/jvm/java/JavacSpecTest.java
@@ -30,26 +30,35 @@
 import com.facebook.buck.core.sourcepath.DefaultBuildTargetSourcePath;
 import com.facebook.buck.core.sourcepath.PathSourcePath;
 import com.facebook.buck.core.sourcepath.SourcePath;
+import com.facebook.buck.core.sourcepath.resolver.SourcePathResolver;
+import com.facebook.buck.core.sourcepath.resolver.impl.DefaultSourcePathResolver;
 import com.facebook.buck.model.BuildTargetFactory;
 import com.facebook.buck.rules.FakeSourcePath;
 import com.facebook.buck.testutil.FakeProjectFilesystem;
+import com.facebook.buck.testutil.TemporaryPaths;
 import com.facebook.buck.util.types.Either;
 import com.google.common.collect.ImmutableList;
+import java.io.IOException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import org.hamcrest.Matchers;
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
 
 public class JavacSpecTest {
   private ActionGraphBuilder graphBuilder;
+  private SourcePathResolver sourcePathResolver;
   private SourcePathRuleFinder ruleFinder;
   private JavacSpec.Builder specBuilder;
 
+  @Rule public TemporaryPaths tmp = new TemporaryPaths();
+
   @Before
   public void setUp() {
     graphBuilder = new TestActionGraphBuilder();
     ruleFinder = new SourcePathRuleFinder(graphBuilder);
+    sourcePathResolver = DefaultSourcePathResolver.from(ruleFinder);
     specBuilder = JavacSpec.builder();
   }
 
@@ -70,33 +79,33 @@ public void returnsBuiltInJavacWhenCompilerArgHasDefault() {
   }
 
   @Test
-  public void returnsExternalCompilerIfJavacPathPresent() {
-    Path externalPath = Paths.get("/foo/bar/path/to/javac");
-    SourcePath javacPath = FakeSourcePath.of(externalPath);
+  public void returnsExternalCompilerIfJavacPathPresent() throws IOException {
+    Path externalPath = tmp.newExecutableFile();
 
+    SourcePath javacPath = FakeSourcePath.of(externalPath);
     specBuilder.setJavacPath(Either.ofRight(javacPath));
     ExternalJavac javac = (ExternalJavac) getJavac();
-    assertTrue(javac.getActualPath().isLeft());
-    assertEquals(javacPath, javac.getActualPath().getLeft());
+
+    assertEquals(
+        ImmutableList.of(externalPath.toString()), javac.getCommandPrefix(sourcePathResolver));
   }
 
   @Test
-  public void returnsExternalCompilerIfCompilerArgHasPath() {
-    Path externalJavac = Paths.get("/foo/bar/javac.exe").toAbsolutePath();
+  public void returnsExternalCompilerIfCompilerArgHasPath() throws IOException {
+    Path externalJavac = tmp.newExecutableFile();
     SourcePath sourcePath = FakeSourcePath.of(externalJavac.toString());
     Either<BuiltInJavac, SourcePath> either = Either.ofRight(sourcePath);
 
     specBuilder.setCompiler(either);
     ExternalJavac javac = (ExternalJavac) getJavac();
 
-    assertTrue(javac.getActualPath().isLeft());
-    PathSourcePath actualPath = javac.getActualPath().getLeft();
-    assertEquals(sourcePath, actualPath);
+    assertEquals(
+        ImmutableList.of(externalJavac.toString()), javac.getCommandPrefix(sourcePathResolver));
   }
 
   @Test
-  public void compilerArgTakesPrecedenceOverJavacPathArg() {
-    Path externalJavacPath = Paths.get("/foo/bar/javac.exe").toAbsolutePath();
+  public void compilerArgTakesPrecedenceOverJavacPathArg() throws IOException {
+    Path externalJavacPath = tmp.newExecutableFile();
     SourcePath sourcePath = FakeSourcePath.of(externalJavacPath.toString());
     Either<BuiltInJavac, SourcePath> either = Either.ofRight(sourcePath);
 
@@ -105,8 +114,8 @@ public void compilerArgTakesPrecedenceOverJavacPathArg() {
         .setJavacPath(Either.ofLeft(FakeSourcePath.of("does-not-exist")));
     ExternalJavac javac = (ExternalJavac) getJavac();
 
-    assertTrue(javac.getActualPath().isLeft());
-    assertEquals(sourcePath, javac.getActualPath().getLeft());
+    assertEquals(
+        ImmutableList.of(externalJavacPath.toString()), javac.getCommandPrefix(sourcePathResolver));
   }
 
   @Test