diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Modules.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Modules.java
index 0cef9cc6602..5a1fe70dd9b 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Modules.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Modules.java
@@ -37,7 +37,7 @@ import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
 import java.util.Set;
-import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -236,6 +236,7 @@ public class Modules extends JCTree.Visitor {
                 setupAllModules(); //initialize the module graph
                 Assert.checkNonNull(allModules);
                 inInitModules = false;
+                return allModules;
             }, null);
         } finally {
             inInitModules = false;
@@ -249,10 +250,11 @@ public class Modules extends JCTree.Visitor {
             //the next steps may query if the current module participates in preview,
             //and that requires a completed java.base:
             syms.java_base.complete();
+            return modules;
         }, c);
     }
 
-    private boolean enter(List<JCCompilationUnit> trees, Consumer<Set<ModuleSymbol>> init, ClassSymbol c) {
+    private boolean enter(List<JCCompilationUnit> trees, Function<Set<ModuleSymbol>, Set<ModuleSymbol>> init, ClassSymbol c) {
         if (!allowModules) {
             for (JCCompilationUnit tree: trees) {
                 tree.modle = syms.noModule;
@@ -270,10 +272,13 @@ public class Modules extends JCTree.Visitor {
 
             setCompilationUnitModules(trees, roots, c);
 
-            init.accept(roots);
+            Set<ModuleSymbol> initialized = init.apply(roots);
 
-            for (ModuleSymbol msym: roots) {
-                msym.complete();
+            for (ModuleSymbol msym : initialized) {
+                if (msym != syms.unnamedModule ||
+                    roots.contains(syms.unnamedModule)) {
+                    msym.complete();
+                }
             }
         } catch (CompletionFailure ex) {
             chk.completionError(null, ex);
diff --git a/test/langtools/jdk/javadoc/tool/modules/Modules.java b/test/langtools/jdk/javadoc/tool/modules/Modules.java
index d830470bb01..c8028ba5c7e 100644
--- a/test/langtools/jdk/javadoc/tool/modules/Modules.java
+++ b/test/langtools/jdk/javadoc/tool/modules/Modules.java
@@ -672,4 +672,35 @@ public class Modules extends ModuleTestBase {
         checkTypesIncluded("p.P");
     }
 
+    @Test
+    public void testImportModules(Path base) throws Exception {
+        Path src = base.resolve("src");
+        Path mod = Paths.get(src.toString(), "m1");
+        tb.writeJavaFiles(mod,
+                """
+                import module m1;
+                module m1 {
+                    exports p;
+                    uses Service;
+                    provides Service with ServiceImpl;
+                }
+                """,
+                """
+                package p;
+                public interface Service {
+                }
+                """,
+                """
+                package p;
+                public class ServiceImpl implements Service {
+                }
+                """);
+        execTask("--module-source-path", src.toString(),
+                 "--module", "m1");
+        checkModulesSpecified("m1");
+        checkPackagesIncluded("p");
+        checkTypesIncluded("p.Service");
+        checkTypesIncluded("p.ServiceImpl");
+    }
+
 }
diff --git a/test/langtools/tools/javac/modules/AddModulesTest.java b/test/langtools/tools/javac/modules/AddModulesTest.java
index f7a87c592c9..080a5edda27 100644
--- a/test/langtools/tools/javac/modules/AddModulesTest.java
+++ b/test/langtools/tools/javac/modules/AddModulesTest.java
@@ -23,7 +23,7 @@
 
 /*
  * @test
- * @bug 8167975 8173596
+ * @bug 8167975 8173596 8370334
  * @summary Test the --add-modules option
  * @library /tools/lib
  * @modules jdk.compiler/com.sun.tools.javac.api
@@ -35,6 +35,7 @@
 
 import java.nio.file.Path;
 import java.util.Arrays;
+import java.util.List;
 
 import javax.tools.JavaCompiler;
 import javax.tools.JavaCompiler.CompilationTask;
@@ -278,5 +279,39 @@ public class AddModulesTest extends ModuleTestBase {
             Assert.check(t.call());
         }
     }
+
+    @Test //JDK-8370334
+    public void testModuleImportAndAddModules(Path base) throws Exception {
+        Path src = base.resolve("src");
+
+        //module that will be inserted using addModules:
+        Path src_m = src.resolve("m");
+        tb.writeJavaFiles(src_m,
+                          "import module m; module m { exports p1; }",
+                          "package p1; public class C1 { }");
+        //test module:
+        Path src_test = src.resolve("test");
+        tb.writeJavaFiles(src_test,
+                          "import module test; module test { exports p2; }",
+                          "package p2; public class C2 { }");
+
+        Path classes = base.resolve("classes");
+        tb.createDirectories(classes);
+
+        JavaCompiler c = ToolProvider.getSystemJavaCompiler();
+        try (StandardJavaFileManager fm = c.getStandardFileManager(null, null, null)) {
+            List<String> options = List.of(
+                "--module-source-path", src.toString(),
+                "-d", classes.toString()
+            );
+            Iterable<? extends JavaFileObject> files =
+                    fm.getJavaFileObjects(findJavaFiles(src_test));
+
+            CompilationTask t = c.getTask(null, fm, null, options, null, files);
+            t.addModules(Arrays.asList("m"));
+            //expecting no errors/crashes:
+            Assert.check(t.call());
+        }
+    }
 }