diff --git a/annotations/com/intellij/openapi/project/annotations.xml b/annotations/com/intellij/openapi/project/annotations.xml
new file mode 100644
index 00000000000..b6cd1dc558f
--- /dev/null
+++ b/annotations/com/intellij/openapi/project/annotations.xml
@@ -0,0 +1,6 @@
+<root>
+    <item
+        name='com.intellij.openapi.project.DumbService com.intellij.openapi.project.DumbService getInstance(com.intellij.openapi.project.Project)'>
+        <annotation name='org.jetbrains.annotations.NotNull'/>
+    </item>
+</root>
\ No newline at end of file
diff --git a/idea/src/org/jetbrains/jet/plugin/codeInsight/KotlinCopyPasteReferenceProcessor.kt b/idea/src/org/jetbrains/jet/plugin/codeInsight/KotlinCopyPasteReferenceProcessor.kt
index f871ce186e3..291e292c2e5 100644
--- a/idea/src/org/jetbrains/jet/plugin/codeInsight/KotlinCopyPasteReferenceProcessor.kt
+++ b/idea/src/org/jetbrains/jet/plugin/codeInsight/KotlinCopyPasteReferenceProcessor.kt
@@ -68,7 +68,7 @@ import org.jetbrains.jet.lang.resolve.descriptorUtil.isExtension
 public class KotlinCopyPasteReferenceProcessor() : CopyPastePostProcessor<ReferenceTransferableData>() {
 
     override fun extractTransferableData(content: Transferable): List<ReferenceTransferableData> {
-        if (CodeInsightSettings.getInstance()!!.ADD_IMPORTS_ON_PASTE != CodeInsightSettings.NO) {
+        if (CodeInsightSettings.getInstance().ADD_IMPORTS_ON_PASTE != CodeInsightSettings.NO) {
             try {
                 val flavor = ReferenceData.getDataFlavor()
                 if (flavor != null) {
@@ -94,7 +94,7 @@ public class KotlinCopyPasteReferenceProcessor() : CopyPastePostProcessor<Refere
             startOffsets: IntArray,
             endOffsets: IntArray
     ): List<ReferenceTransferableData> {
-        if (file !is JetFile) {
+        if (file !is JetFile || DumbService.getInstance(file.getProject()).isDumb()) {
             return listOf()
         }
 
@@ -184,7 +184,7 @@ public class KotlinCopyPasteReferenceProcessor() : CopyPastePostProcessor<Refere
             indented: Ref<Boolean>,
             values: List<ReferenceTransferableData>
     ) {
-        if (DumbService.getInstance(project)!!.isDumb()) {
+        if (DumbService.getInstance(project).isDumb()) {
             return
         }
         val document = editor.getDocument()
@@ -289,7 +289,7 @@ public class KotlinCopyPasteReferenceProcessor() : CopyPastePostProcessor<Refere
     }
 
     private fun showRestoreReferencesDialog(project: Project, referencesToRestore: List<ReferenceToRestoreData>): Collection<ReferenceToRestoreData> {
-        val shouldShowDialog = CodeInsightSettings.getInstance()!!.ADD_IMPORTS_ON_PASTE == CodeInsightSettings.ASK
+        val shouldShowDialog = CodeInsightSettings.getInstance().ADD_IMPORTS_ON_PASTE == CodeInsightSettings.ASK
         if (!shouldShowDialog || referencesToRestore.isEmpty()) {
             return referencesToRestore
         }