IDEA complains about missing classes after updating the Gradle Intellij Plugin to 1.10.0

In my plugin project I tried to update the Gradle plugin from 1.9.0 to 1.10.0:

// Gradle IntelliJ Plugin
id("org.jetbrains.intellij") version "1.10.0"

With gradle plugin 1.9.0 everything works fine.  I can compile the project via IDEA as well as via console (./gradlew buildPlugin).
But with gradle plugin 1.10.0 I can only compile it on console anymore.  IDEA suddenly complains about missing classes such as com.intellij.psi.PsiElement, which is actually covered by

<depends>com.intellij.modules.lang</depends>