diff --git a/kotlin-checks-test-sources/src/main/kotlin/checks/CollectionShouldBeImmutableCheckSample.kt b/kotlin-checks-test-sources/src/main/kotlin/checks/CollectionShouldBeImmutableCheckSample.kt
index 4102258d1..ec96d5db9 100644
--- a/kotlin-checks-test-sources/src/main/kotlin/checks/CollectionShouldBeImmutableCheckSample.kt
+++ b/kotlin-checks-test-sources/src/main/kotlin/checks/CollectionShouldBeImmutableCheckSample.kt
@@ -249,4 +249,7 @@ class CollectionShouldBeImmutableCheckSample {
 
 private fun nonCompliantParameterOnFileLevel(list: MutableList<Int>): Int { // Noncompliant
     return list.reduce { acc, it -> acc + it}
-}
\ No newline at end of file
+}
+
+// https://sonarsource.atlassian.net/browse/SONARKT-388
+private fun <T> intersectionType(t: T) = if (t is String) listOf(t) else emptyList()
diff --git a/sonar-kotlin-checks/src/main/java/org/sonarsource/kotlin/checks/CollectionShouldBeImmutableCheck.kt b/sonar-kotlin-checks/src/main/java/org/sonarsource/kotlin/checks/CollectionShouldBeImmutableCheck.kt
index 0f77e777e..3d0848717 100644
--- a/sonar-kotlin-checks/src/main/java/org/sonarsource/kotlin/checks/CollectionShouldBeImmutableCheck.kt
+++ b/sonar-kotlin-checks/src/main/java/org/sonarsource/kotlin/checks/CollectionShouldBeImmutableCheck.kt
@@ -153,7 +153,10 @@ class CollectionShouldBeImmutableCheck : AbstractCheck() {
                 val functionDescriptor = call.getResolvedCall(bindingContext)?.resultingDescriptor
                 val parameterTypes = functionDescriptor?.valueParameters
                 if (parameterTypes != null) {
-                    val fullyQualifiedTypes = parameterTypes.map { it.type.getKotlinTypeFqName(false) }
+                    val fullyQualifiedTypes = parameterTypes.map {
+                        if (it.type.constructor.declarationDescriptor == null) null
+                        else it.type.getKotlinTypeFqName(false)
+                    }
                     call.valueArguments.zip(fullyQualifiedTypes).filter { it.second in mutableCollections }.map { it.first }
                 } else {
                     call.valueArguments