diff --git a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/scoping/UriResolver.java b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/scoping/UriResolver.java
index bb960d83..c403e630 100644
--- a/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/scoping/UriResolver.java
+++ b/com.google.eclipse.protobuf.ui/src/com/google/eclipse/protobuf/ui/scoping/UriResolver.java
@@ -24,6 +24,7 @@
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.emf.common.util.URI;
+import org.eclipse.jdt.core.IClasspathContainer;
 import org.eclipse.jdt.core.IClasspathEntry;
 import org.eclipse.jdt.core.IJavaProject;
 import org.eclipse.jdt.core.IPackageFragmentRoot;
@@ -35,6 +36,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.function.Consumer;
 
 /**
  * Resolves URIs.
@@ -97,27 +99,42 @@ private String resolveUriInternal(String importUri, URI declaringResourceUri, IP
 		if (project.isOpen() && JavaProject.hasJavaNature(project)) {
   		  ArrayList<DirectoryPath> paths = new ArrayList<>();
   		  try {
-	    		  IJavaProject javaProject = JavaCore.create(project);
-	    		  for (IClasspathEntry classpathEntry : javaProject.getRawClasspath()) {
-	    			  if (classpathEntry.getContentKind() == IPackageFragmentRoot.K_BINARY) {
-	    				  if (classpathEntry.getPath().toOSString().toLowerCase().endsWith(".jar")) {
-	    					  IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
-
-	    					  if (classpathEntry.getEntryKind() == IClasspathEntry.CPE_LIBRARY) {
-	    					      IPath cpPath = classpathEntry.getPath();
-	    					      IResource res = root.findMember(cpPath);
-	    					      // If res is null, the path is absolute (it's an external jar)
-	    					      String path;
-	    					      if (res == null) {
-	    					          path = cpPath.toOSString();
-	    					      } else {
-	    					          path = "${workspace_loc:" + res.getFullPath().toOSString() + "}";
-	    					      }
-	    					      paths.add(DirectoryPath.parse(path, project));
-	    					  }
-	    				  }
-	    			  }
-	    		  }
+				final Consumer<IClasspathEntry> cpeConsumer = new Consumer<IClasspathEntry>() {
+					@Override
+					public void accept(IClasspathEntry classpathEntry) {
+						if (classpathEntry.getPath().toOSString().toLowerCase().endsWith(".jar")) {
+					  IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
+				
+					  if (classpathEntry.getEntryKind() == IClasspathEntry.CPE_LIBRARY) {
+					      IPath cpPath = classpathEntry.getPath();
+					      IResource res = root.findMember(cpPath);
+					      // If res is null, the path is absolute (it's an external jar)
+					      String path;
+					      if (res == null) {
+					          path = cpPath.toOSString();
+					      } else {
+					          path = "${workspace_loc:" + res.getFullPath().toOSString() + "}";
+						      }
+						      paths.add(DirectoryPath.parse(path, project));
+						  }
+					  }  					
+					}  				
+				};
+  			  
+  			  
+				IJavaProject javaProject = JavaCore.create(project);    		  
+				for (IClasspathEntry classpathEntry : javaProject.getRawClasspath()) {
+					if (classpathEntry.getEntryKind() == IClasspathEntry.CPE_CONTAINER) {
+						final IClasspathContainer container = JavaCore.getClasspathContainer(classpathEntry.getPath(), javaProject);
+						if(container.getKind() != IClasspathContainer.K_SYSTEM && container.getKind() != IClasspathContainer.K_DEFAULT_SYSTEM) {
+							for (IClasspathEntry containedClasspathEntry : container.getClasspathEntries()) {
+								cpeConsumer.accept(containedClasspathEntry);
+							}
+						}
+					} else if (classpathEntry.getContentKind() == IPackageFragmentRoot.K_BINARY) {
+						cpeConsumer.accept(classpathEntry);
+					}
+				}
   		  } catch(JavaModelException e) {
   			  // ignored
   		  }