diff --git a/python/psi-api/src/com/jetbrains/python/psi/resolve/PyCanonicalPathProvider.java b/python/psi-api/src/com/jetbrains/python/psi/resolve/PyCanonicalPathProvider.java
index 5b6e4f78655d..14be29b39f85 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/resolve/PyCanonicalPathProvider.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/resolve/PyCanonicalPathProvider.java
@@ -3,6 +3,7 @@ package com.jetbrains.python.psi.resolve;
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.psi.PsiElement;
 import com.jetbrains.python.psi.impl.PyQualifiedName;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 /**
@@ -21,5 +22,5 @@ public interface PyCanonicalPathProvider {
    * @return the qualified name to use in the import statement, or null if no replacement is necessary.
    */
   @Nullable
-  PyQualifiedName getCanonicalPath(PyQualifiedName qName, PsiElement foothold);
+  PyQualifiedName getCanonicalPath(@NotNull PyQualifiedName qName, @Nullable PsiElement foothold);
 }
diff --git a/python/src/com/jetbrains/python/codeInsight/stdlib/PyStdlibCanonicalPathProvider.java b/python/src/com/jetbrains/python/codeInsight/stdlib/PyStdlibCanonicalPathProvider.java
index b6c9791067cf..53ecd40b7f3b 100644
--- a/python/src/com/jetbrains/python/codeInsight/stdlib/PyStdlibCanonicalPathProvider.java
+++ b/python/src/com/jetbrains/python/codeInsight/stdlib/PyStdlibCanonicalPathProvider.java
@@ -3,6 +3,7 @@ package com.jetbrains.python.codeInsight.stdlib;
 import com.intellij.psi.PsiElement;
 import com.jetbrains.python.psi.impl.PyQualifiedName;
 import com.jetbrains.python.psi.resolve.PyCanonicalPathProvider;
+import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
@@ -14,7 +15,7 @@ import java.util.List;
 public class PyStdlibCanonicalPathProvider implements PyCanonicalPathProvider {
   @Nullable
   @Override
-  public PyQualifiedName getCanonicalPath(PyQualifiedName qName, PsiElement foothold) {
+  public PyQualifiedName getCanonicalPath(@NotNull PyQualifiedName qName, PsiElement foothold) {
     return restoreStdlibCanonicalPath(qName);
   }