diff --git a/compile/src/main/scala/sbt/compiler/javac/LocalJava.scala b/compile/src/main/scala/sbt/compiler/javac/LocalJava.scala
index 81f4e1293..42ef0ed6e 100644
--- a/compile/src/main/scala/sbt/compiler/javac/LocalJava.scala
+++ b/compile/src/main/scala/sbt/compiler/javac/LocalJava.scala
@@ -66,6 +66,14 @@ final class LocalJavaCompiler(compiler: javax.tools.JavaCompiler) extends JavaCo
     val diagnostics = new DiagnosticsReporter(reporter)
     val fileManager = compiler.getStandardFileManager(diagnostics, null, null)
     val jfiles = fileManager.getJavaFileObjectsFromFiles(sources.asJava)
-    compiler.getTask(logWriter, fileManager, diagnostics, options.asJava, null, jfiles).call()
+
+    // Local Java compiler doesn't accept `-J<flag>` options. We emit a warning if we find
+    // such options and don't pass them to the compiler.
+    val (invalidOptions, cleanedOptions) = options partition (_ startsWith "-J")
+    if (invalidOptions.nonEmpty) {
+      log.warn("Javac is running in 'local' mode. These flags have been removed:")
+      log.warn(invalidOptions.mkString("\t", ", ", ""))
+    }
+    compiler.getTask(logWriter, fileManager, diagnostics, cleanedOptions.asJava, null, jfiles).call()
   }
 }
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