diff --git a/platform/lang-api/src/com/intellij/openapi/projectRoots/impl/UnknownSdkType.java b/platform/lang-api/src/com/intellij/openapi/projectRoots/impl/UnknownSdkType.java
index 97905a81f886..b200efd53349 100644
--- a/platform/lang-api/src/com/intellij/openapi/projectRoots/impl/UnknownSdkType.java
+++ b/platform/lang-api/src/com/intellij/openapi/projectRoots/impl/UnknownSdkType.java
@@ -83,4 +83,9 @@ public class UnknownSdkType extends SdkType{
   public Icon getIcon() {
     return AllIcons.Nodes.UnknownJdk;
   }
+
+  @Override
+  public boolean allowCreationByUser() {
+    return false;
+  }
 }