diff --git a/core-macros/src/main/scala/sbt/internal/util/appmacro/Instance.scala b/core-macros/src/main/scala/sbt/internal/util/appmacro/Instance.scala
index f077ed5ab..5c15a3346 100644
--- a/core-macros/src/main/scala/sbt/internal/util/appmacro/Instance.scala
+++ b/core-macros/src/main/scala/sbt/internal/util/appmacro/Instance.scala
@@ -187,7 +187,9 @@ object Instance {
       qual.foreach(checkQual)
       val vd = util.freshValDef(tpe, qual.pos, functionSym)
       inputs ::= new Input(tpe, qual, vd)
-      util.refVal(selection, vd)
+      // try to workaround https://github.com/scala/bug/issues/12112 by calling Predef.identity(...)
+      val rv = util.refVal(selection, vd)
+      q"scala.Predef.identity[$tpe]($rv: $tpe)"
     }
     def sub(name: String, tpe: Type, qual: Tree, replace: Tree): Converted[c.type] = {
       val tag = c.WeakTypeTag[T](tpe)
diff --git a/sbt/src/sbt-test/project/setting-macro/project/PureExpressionPlugin.scala b/sbt/src/sbt-test/project/setting-macro/project/PureExpressionPlugin.scala
new file mode 100644
index 000000000..f0eea984b
--- /dev/null
+++ b/sbt/src/sbt-test/project/setting-macro/project/PureExpressionPlugin.scala
@@ -0,0 +1,15 @@
+package pkgtest
+
+import sbt._, Keys._
+
+// https://github.com/scala/bug/issues/12112
+object PureExpressionPlugin extends AutoPlugin {
+  lazy val testPureExpression = taskKey[Unit]("")
+  override def projectSettings: Seq[Setting[_]] = {
+    testPureExpression := {
+      updateFull.value
+      (Compile / compile).value
+      (Test / test).value
+    }
+  }
+}
diff --git a/sbt/src/sbt-test/project/setting-macro/project/plugins.sbt b/sbt/src/sbt-test/project/setting-macro/project/plugins.sbt
new file mode 100644
index 000000000..9674e9d5f
--- /dev/null
+++ b/sbt/src/sbt-test/project/setting-macro/project/plugins.sbt
@@ -0,0 +1 @@
+Compile / scalacOptions += "-Xfatal-warnings"