diff --git a/compiler/src/dotty/tools/dotc/Run.scala b/compiler/src/dotty/tools/dotc/Run.scala
index bcab1c50db65..85e253cadcd8 100644
--- a/compiler/src/dotty/tools/dotc/Run.scala
+++ b/compiler/src/dotty/tools/dotc/Run.scala
@@ -19,9 +19,10 @@ import transform.TreeChecker
 import rewrite.Rewrites
 import java.io.{BufferedWriter, OutputStreamWriter}
 
-import dotty.tools.dotc.profile.Profiler
+import profile.Profiler
 import printing.XprintMode
 import parsing.Parsers.Parser
+import parsing.JavaParsers.JavaParser
 import typer.ImplicitRunInfo
 import collection.mutable
 
@@ -209,7 +210,9 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
       lateFiles += file
       val unit = new CompilationUnit(getSource(file.path))
       def process()(implicit ctx: Context) = {
-        unit.untpdTree = new Parser(unit.source).parse()
+        unit.untpdTree =
+          if (unit.isJava) new JavaParser(unit.source).parse()
+          else new Parser(unit.source).parse()
         ctx.typer.lateEnter(unit.untpdTree)
         def typeCheckUnit() = unit.tpdTree = ctx.typer.typedExpr(unit.untpdTree)
         if (typeCheck)
diff --git a/compiler/src/dotty/tools/dotc/core/SymbolLoaders.scala b/compiler/src/dotty/tools/dotc/core/SymbolLoaders.scala
index fc3acef8c826..87d810e9cb5e 100644
--- a/compiler/src/dotty/tools/dotc/core/SymbolLoaders.scala
+++ b/compiler/src/dotty/tools/dotc/core/SymbolLoaders.scala
@@ -16,6 +16,7 @@ import Decorators._
 import scala.util.control.NonFatal
 import ast.Trees._
 import ast.tpd
+import parsing.JavaParsers.OutlineJavaParser
 import parsing.Parsers.OutlineParser
 import reporting.trace
 
@@ -154,7 +155,10 @@ object SymbolLoaders {
             case _ =>
           }
 
-          traverse(new OutlineParser(unit.source).parse(), Nil)
+          traverse(
+            if (unit.isJava) new OutlineJavaParser(unit.source).parse()
+            else new OutlineParser(unit.source).parse(),
+            Nil)
         }
 
         val unit = new CompilationUnit(ctx.run.getSource(src.path))
diff --git a/compiler/src/dotty/tools/dotc/parsing/JavaParsers.scala b/compiler/src/dotty/tools/dotc/parsing/JavaParsers.scala
index 5c203d123f4a..f22afb941c73 100644
--- a/compiler/src/dotty/tools/dotc/parsing/JavaParsers.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/JavaParsers.scala
@@ -907,4 +907,18 @@ object JavaParsers {
       unit
     }
   }
+
+
+  /** OutlineJavaParser parses top-level declarations in `source` to find declared classes, ignoring their bodies (which
+   *  must only have balanced braces). This is used to map class names to defining sources.
+   *  This is necessary even for Java, because the filename defining a non-public classes cannot be determined from the
+   *  classname alone.
+   */
+  class OutlineJavaParser(source: SourceFile)(implicit ctx: Context) extends JavaParser(source) with OutlineParserCommon {
+    override def skipBracesHook() = None
+    override def typeBody(leadingToken: Int, parentName: Name, parentTParams: List[TypeDef]): (List[Tree], List[Tree]) = {
+      skipBraces()
+      (List(EmptyValDef), List(EmptyTree))
+    }
+  }
 }
diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
index ee83866d48c9..991255e913fa 100644
--- a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -130,6 +130,23 @@ object Parsers {
       ctx.error(msg, source atPos pos)
   }
 
+  trait OutlineParserCommon extends ParserCommon {
+    def accept(token: Int): Int
+
+    def skipBracesHook(): Option[Tree]
+    def skipBraces(): Unit = {
+      accept(LBRACE)
+      var openBraces = 1
+      while (in.token != EOF && openBraces > 0) {
+        skipBracesHook() getOrElse {
+          if (in.token == LBRACE) openBraces += 1
+          else if (in.token == RBRACE) openBraces -= 1
+          in.nextToken()
+        }
+      }
+    }
+  }
+
   class Parser(source: SourceFile)(implicit ctx: Context) extends ParserCommon(source) {
 
     val in: Scanner = new Scanner(source)
@@ -2638,24 +2655,22 @@ object Parsers {
   }
 
 
-  class OutlineParser(source: SourceFile)(implicit ctx: Context) extends Parser(source) {
+  /** OutlineParser parses top-level declarations in `source` to find declared classes, ignoring their bodies (which
+   *  must only have balanced braces). This is used to map class names to defining sources.
+   */
+  class OutlineParser(source: SourceFile)(implicit ctx: Context) extends Parser(source) with OutlineParserCommon {
 
-    def skipBraces[T](body: T): T = {
-      accept(LBRACE)
-      var openBraces = 1
-      while (in.token != EOF && openBraces > 0) {
-        if (in.token == XMLSTART) xmlLiteral()
-        else {
-          if (in.token == LBRACE) openBraces += 1
-          else if (in.token == RBRACE) openBraces -= 1
-          in.nextToken()
-        }
-      }
-      body
-    }
+    def skipBracesHook(): Option[Tree] =
+      if (in.token == XMLSTART) Some(xmlLiteral()) else None
 
-    override def blockExpr(): Tree = skipBraces(EmptyTree)
+    override def blockExpr(): Tree = {
+      skipBraces()
+      EmptyTree
+    }
 
-    override def templateBody() = skipBraces((EmptyValDef, List(EmptyTree)))
+    override def templateBody() = {
+      skipBraces()
+      (EmptyValDef, List(EmptyTree))
+    }
   }
 }
diff --git a/compiler/src/dotty/tools/dotc/parsing/Scanners.scala b/compiler/src/dotty/tools/dotc/parsing/Scanners.scala
index 7aa2dc4d36eb..694386cef3b3 100644
--- a/compiler/src/dotty/tools/dotc/parsing/Scanners.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/Scanners.scala
@@ -57,6 +57,7 @@ object Scanners {
 
   abstract class ScannerCommon(source: SourceFile)(implicit ctx: Context) extends CharArrayReader with TokenData {
     val buf = source.content
+    def nextToken(): Unit
 
     // Errors -----------------------------------------------------------------
 
diff --git a/compiler/test/dotty/tools/dotc/CompilationTests.scala b/compiler/test/dotty/tools/dotc/CompilationTests.scala
index 90521d3acca4..7dc338710a6c 100644
--- a/compiler/test/dotty/tools/dotc/CompilationTests.scala
+++ b/compiler/test/dotty/tools/dotc/CompilationTests.scala
@@ -47,6 +47,7 @@ class CompilationTests extends ParallelTesting {
     compileFile("tests/pos-special/completeFromSource/Test.scala", defaultOptions.and("-sourcepath", "tests/pos-special")) +
     compileFile("tests/pos-special/completeFromSource/Test2.scala", defaultOptions.and("-sourcepath", "tests/pos-special")) +
     compileFile("tests/pos-special/completeFromSource/Test3.scala", defaultOptions.and("-sourcepath", "tests/pos-special", "-scansource")) +
+    compileFile("tests/pos-special/completeFromSource/nested/Test4.scala", defaultOptions.and("-sourcepath", "tests/pos-special", "-scansource")) +
     compileFilesInDir("tests/pos-special/fatal-warnings", defaultOptions.and("-Xfatal-warnings")) +
     compileList(
       "compileMixed",
@@ -158,7 +159,8 @@ class CompilationTests extends ParallelTesting {
     compileFile("tests/neg-custom-args/i4372.scala", allowDeepSubtypes) +
     compileFile("tests/neg-custom-args/i1754.scala", allowDeepSubtypes) +
     compileFilesInDir("tests/neg-custom-args/isInstanceOf", allowDeepSubtypes and "-Xfatal-warnings") +
-    compileFile("tests/neg-custom-args/i3627.scala", allowDeepSubtypes)
+    compileFile("tests/neg-custom-args/i3627.scala", allowDeepSubtypes) +
+    compileFile("tests/neg-custom-args/completeFromSource/nested/Test1.scala", defaultOptions.and("-sourcepath", "tests/neg-custom-args", "-scansource"))
   }.checkExpectedErrors()
 
   // Run tests -----------------------------------------------------------------
diff --git a/tests/neg-custom-args/completeFromSource/nested/D.java b/tests/neg-custom-args/completeFromSource/nested/D.java
new file mode 100644
index 000000000000..e437b32ed0b2
--- /dev/null
+++ b/tests/neg-custom-args/completeFromSource/nested/D.java
@@ -0,0 +1,18 @@
+package completeFromSource.nested;
+
+public class D {
+    public D(int i) {
+
+    }
+    public String thisIsD(int i) {
+        return java.lang.Integer.toString(i);
+    }
+}
+
+class E {
+    public E(String s) {}
+
+    public String thisIsE(int i) {
+        return java.lang.Integer.toString(i);
+    }
+}
diff --git a/tests/neg-custom-args/completeFromSource/nested/Test1.scala b/tests/neg-custom-args/completeFromSource/nested/Test1.scala
new file mode 100644
index 000000000000..baac82e3234c
--- /dev/null
+++ b/tests/neg-custom-args/completeFromSource/nested/Test1.scala
@@ -0,0 +1,10 @@
+package completeFromSource.nested
+
+class Test4 {
+
+  val d = new D(1)
+  val e = new E("xx")
+
+  d.thisIsD(1)
+  e.thisIsE() // error
+}
diff --git a/tests/pos-special/completeFromSource/nested/D.java b/tests/pos-special/completeFromSource/nested/D.java
new file mode 100644
index 000000000000..e437b32ed0b2
--- /dev/null
+++ b/tests/pos-special/completeFromSource/nested/D.java
@@ -0,0 +1,18 @@
+package completeFromSource.nested;
+
+public class D {
+    public D(int i) {
+
+    }
+    public String thisIsD(int i) {
+        return java.lang.Integer.toString(i);
+    }
+}
+
+class E {
+    public E(String s) {}
+
+    public String thisIsE(int i) {
+        return java.lang.Integer.toString(i);
+    }
+}
diff --git a/tests/pos-special/completeFromSource/nested/Test4.scala b/tests/pos-special/completeFromSource/nested/Test4.scala
new file mode 100644
index 000000000000..daa06d12c426
--- /dev/null
+++ b/tests/pos-special/completeFromSource/nested/Test4.scala
@@ -0,0 +1,10 @@
+package completeFromSource.nested
+
+class Test4 {
+
+  val d = new D(1)
+  val e = new E("xx")
+
+  d.thisIsD(1)
+  e.thisIsE(2)
+}