diff --git a/src/java.base/share/classes/module-info.java b/src/java.base/share/classes/module-info.java
index 7486fdd825c..614842e064c 100644
--- a/src/java.base/share/classes/module-info.java
+++ b/src/java.base/share/classes/module-info.java
@@ -155,7 +155,6 @@ module java.base {
     exports jdk.internal.javac to
         java.compiler,
         java.desktop, // for ScopedValue
-        java.se, // for ParticipatesInPreview
         jdk.compiler,
         jdk.incubator.vector, // participates in preview features
         jdk.jartool, // participates in preview features
diff --git a/src/java.se/share/classes/module-info.java b/src/java.se/share/classes/module-info.java
index 0fa5a561dec..79b1f746cb0 100644
--- a/src/java.se/share/classes/module-info.java
+++ b/src/java.se/share/classes/module-info.java
@@ -23,8 +23,6 @@
  * questions.
  */
 
-import jdk.internal.javac.ParticipatesInPreview;
-
 /**
  * Defines the API of the Java SE Platform.
  *
@@ -40,7 +38,6 @@ import jdk.internal.javac.ParticipatesInPreview;
  * @moduleGraph
  * @since 9
  */
-@ParticipatesInPreview
 module java.se {
     requires transitive java.base;
     requires transitive java.compiler;
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Directive.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Directive.java
index cf942dab5cd..f41866ddb6a 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Directive.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Directive.java
@@ -76,7 +76,7 @@ public abstract class Directive implements ModuleElement.Directive {
 
         @Override
         public String toString() {
-            return String.format("ACC_%s (0x%04x", name(), value);
+            return String.format("ACC_%s (0x%04x)", name(), value);
         }
     }
 
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java
index 5a684a1cc59..4ce9147f6f5 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/code/Preview.java
@@ -152,7 +152,9 @@ public class Preview {
         // s participates in the preview API
         return syms.java_base.exports.stream()
                 .filter(ed -> ed.packge.fullname == names.jdk_internal_javac)
-                .anyMatch(ed -> ed.modules.contains(m));
+                .anyMatch(ed -> ed.modules.contains(m)) ||
+               //the specification lists the java.se module as participating in preview:
+               m.name == names.java_se;
     }
 
     /**
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
index 2e7183dfbed..ef20152cc7d 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
@@ -3887,7 +3887,7 @@ compiler.misc.cant.resolve.modules=\
     cannot resolve modules
 
 compiler.misc.bad.requires.flag=\
-    bad requires flag: {0}
+    invalid flag for "requires java.base": {0}
 
 # 0: string
 compiler.err.invalid.module.specifier=\
diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java
index 6c48490cf16..d9aec7c4592 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/util/Names.java
@@ -127,6 +127,7 @@ public class Names {
 
     // module names
     public final Name java_base;
+    public final Name java_se;
     public final Name jdk_unsupported;
 
     // attribute names
@@ -315,6 +316,7 @@ public class Names {
 
         // module names
         java_base = fromString("java.base");
+        java_se = fromString("java.se");
         jdk_unsupported = fromString("jdk.unsupported");
 
         // attribute names
diff --git a/test/langtools/tools/javac/ImportModule.java b/test/langtools/tools/javac/ImportModule.java
index 1224a9d7470..ac00ea823f1 100644
--- a/test/langtools/tools/javac/ImportModule.java
+++ b/test/langtools/tools/javac/ImportModule.java
@@ -23,7 +23,7 @@
 
 /**
  * @test
- * @bug 8328481 8332236 8332890
+ * @bug 8328481 8332236 8332890 8344647
  * @summary Check behavior of module imports.
  * @library /tools/lib
  * @modules java.logging
@@ -33,7 +33,7 @@
  *          jdk.compiler/com.sun.tools.javac.util
  * @build toolbox.ToolBox toolbox.JavacTask
  * @run main ImportModule
-*/
+ */
 
 import com.sun.source.tree.Tree;
 import com.sun.source.util.TaskEvent;
@@ -829,6 +829,7 @@ public class ImportModule extends TestRunner {
         }
     }
 
+    @Test
     public void testPackageImportDisambiguates(Path base) throws Exception {
         Path current = base.resolve(".");
         Path src = current.resolve("src");
@@ -919,4 +920,50 @@ public class ImportModule extends TestRunner {
                 .run(Task.Expect.SUCCESS)
                 .writeAll();
     }
+
+    @Test //JDK-8344647
+    public void testJavaBaseOverride(Path base) throws Exception {
+        Path current = base.resolve(".");
+        Path src = current.resolve("src");
+        Path javaBaseClasses = current.resolve("javaBaseClasses");
+        Path javaBase = src.resolve("java.base");
+        tb.writeJavaFiles(javaBase,
+                          """
+                          module java.base {
+                             exports java.lang;
+                          }
+                          """,
+                          """
+                          package java.lang;
+                          public class Object {}
+                          """);
+
+        Files.createDirectories(javaBaseClasses);
+
+        new JavacTask(tb)
+                .options("--patch-module", "java.base=" + src.toString())
+                .outdir(javaBaseClasses)
+                .files(tb.findJavaFiles(src))
+                .run(Task.Expect.SUCCESS)
+                .writeAll()
+                .getOutputLines(Task.OutputKind.DIRECT);
+
+        Path test = current.resolve("test");
+        tb.writeJavaFiles(test,
+                          """
+                          module test {
+                              requires java.se;
+                          }
+                          """);
+
+        Path classes = current.resolve("classes");
+        Files.createDirectories(classes);
+
+        new JavacTask(tb)
+                .options("--patch-module", "java.base=" + javaBaseClasses.toString())
+                .outdir(classes)
+                .files(tb.findJavaFiles(test))
+                .run(Task.Expect.SUCCESS)
+                .writeAll();
+    }
 }
diff --git a/test/langtools/tools/javac/modules/AnnotationsOnModules.java b/test/langtools/tools/javac/modules/AnnotationsOnModules.java
index 65019854360..291633b4fb2 100644
--- a/test/langtools/tools/javac/modules/AnnotationsOnModules.java
+++ b/test/langtools/tools/javac/modules/AnnotationsOnModules.java
@@ -804,7 +804,7 @@ public class AnnotationsOnModules extends ModuleTestBase {
                 .writeAll()
                 .getOutputLines(OutputKind.DIRECT);
         List<String> expectedErrors = List.of(
-            "- compiler.err.cant.access: m.module-info, (compiler.misc.bad.class.file.header: module-info.class, (compiler.misc.bad.requires.flag: ACC_TRANSITIVE (0x0020))",
+            "- compiler.err.cant.access: m.module-info, (compiler.misc.bad.class.file.header: module-info.class, (compiler.misc.bad.requires.flag: ACC_TRANSITIVE (0x0020)))",
             "1 error"
         );