diff --git a/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt b/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
index 76f82239400..a8b6598eeaa 100644
--- a/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
+++ b/compiler/resolution.common/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
@@ -437,6 +437,9 @@ class NewConstraintSystemImpl(
     override fun hasUpperOrEqualUnitConstraint(type: KotlinTypeMarker): Boolean {
         checkState(State.BUILDING, State.COMPLETION, State.FREEZED)
         val constraints = storage.notFixedTypeVariables[type.typeConstructor()]?.constraints ?: return false
-        return constraints.any { (it.kind == ConstraintKind.UPPER || it.kind == ConstraintKind.EQUALITY) && it.type.isUnit() }
+        return constraints.any {
+            (it.kind == ConstraintKind.UPPER || it.kind == ConstraintKind.EQUALITY) &&
+                    it.type.lowerBoundIfFlexible().isUnit()
+        }
     }
 }