diff --git a/python/src/com/jetbrains/python/packaging/PyPIPackageUtil.java b/python/src/com/jetbrains/python/packaging/PyPIPackageUtil.java
index bcccbcbd9198..15d01d69bc6d 100644
--- a/python/src/com/jetbrains/python/packaging/PyPIPackageUtil.java
+++ b/python/src/com/jetbrains/python/packaging/PyPIPackageUtil.java
@@ -159,7 +159,7 @@ public class PyPIPackageUtil {
   }
 
   @NotNull
-  public List<RepoPackage> getAdditionalPackages(List<String> repositories) {
+  public List<RepoPackage> getAdditionalPackages(@NotNull List<String> repositories) {
     return StreamEx.of(myAdditionalPackages.getAllPresent(repositories).values()).flatMap(StreamEx::of).toList();
   }
 
diff --git a/python/src/com/jetbrains/python/packaging/ui/PyPackageManagementService.java b/python/src/com/jetbrains/python/packaging/ui/PyPackageManagementService.java
index 0f4c6ef54a8d..f58ddc8ce4cf 100644
--- a/python/src/com/jetbrains/python/packaging/ui/PyPackageManagementService.java
+++ b/python/src/com/jetbrains/python/packaging/ui/PyPackageManagementService.java
@@ -124,6 +124,7 @@ public class PyPackageManagementService extends PackageManagementServiceEx {
     return result;
   }
 
+  @NotNull
   private static List<String> getAdditionalRepositories() {
     return PyPackageService.getInstance().additionalRepositories;
   }