diff --git a/compiler/testData/foreignAnnotations/tests/findBugsSimple.txt b/compiler/testData/foreignAnnotations/tests/findBugsSimple.txt
index d08da15a469..b5ada9fb616 100644
--- a/compiler/testData/foreignAnnotations/tests/findBugsSimple.txt
+++ b/compiler/testData/foreignAnnotations/tests/findBugsSimple.txt
@@ -7,7 +7,7 @@ public open class A {
     @edu.umd.cs.findbugs.annotations.Nullable public final var field: kotlin.String?
     @edu.umd.cs.findbugs.annotations.NonNull public open fun bar(): kotlin.String
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    @edu.umd.cs.findbugs.annotations.PossiblyNull public open fun foo(/*0*/ @edu.umd.cs.findbugs.annotations.NonNull x: kotlin.String, /*1*/ @edu.umd.cs.findbugs.annotations.UnknownNullness y: kotlin.CharSequence?): kotlin.String?
+    @edu.umd.cs.findbugs.annotations.PossiblyNull public open fun foo(/*0*/ @edu.umd.cs.findbugs.annotations.NonNull x: kotlin.String, /*1*/ @edu.umd.cs.findbugs.annotations.UnknownNullness y: kotlin.CharSequence!): kotlin.String?
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
diff --git a/compiler/testData/foreignAnnotations/tests/jsr305Strange.kt b/compiler/testData/foreignAnnotations/tests/jsr305Strange.kt
index 6c54c2ab355..57654f9cb8c 100644
--- a/compiler/testData/foreignAnnotations/tests/jsr305Strange.kt
+++ b/compiler/testData/foreignAnnotations/tests/jsr305Strange.kt
@@ -30,5 +30,5 @@ fun main(a: A) {
     a.bar()<!UNNECESSARY_NOT_NULL_ASSERTION!>!!<!>.length
 
     a.field?.length
-    a.field<!UNSAFE_CALL!>.<!>length
+    a.field.length
 }
diff --git a/compiler/testData/foreignAnnotations/tests/jsr305Strange.txt b/compiler/testData/foreignAnnotations/tests/jsr305Strange.txt
index 02da742751d..25bdaa38663 100644
--- a/compiler/testData/foreignAnnotations/tests/jsr305Strange.txt
+++ b/compiler/testData/foreignAnnotations/tests/jsr305Strange.txt
@@ -4,10 +4,10 @@ public fun main(/*0*/ a: A): kotlin.Unit
 
 public open class A {
     public constructor A()
-    @javax.annotation.Nonnull(when = When.UNKNOWN) public final var field: kotlin.String?
+    @javax.annotation.Nonnull(when = When.UNKNOWN) public final var field: kotlin.String!
     @javax.annotation.Nonnull public open fun bar(): kotlin.String
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    @javax.annotation.Nonnull(when = When.MAYBE) public open fun foo(/*0*/ @javax.annotation.Nonnull(when = When.ALWAYS) x: kotlin.String, /*1*/ @javax.annotation.Nonnull(when = When.NEVER) y: kotlin.CharSequence?): kotlin.String?
+    @javax.annotation.Nonnull(when = When.MAYBE) public open fun foo(/*0*/ @javax.annotation.Nonnull(when = When.ALWAYS) x: kotlin.String, /*1*/ @javax.annotation.Nonnull(when = When.NEVER) y: kotlin.CharSequence!): kotlin.String?
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
diff --git a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/typeEnhancement/signatureEnhancement.kt b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/typeEnhancement/signatureEnhancement.kt
index 19b404ca825..260f735c39c 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/typeEnhancement/signatureEnhancement.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/typeEnhancement/signatureEnhancement.kt
@@ -59,11 +59,18 @@ class SignatureEnhancement(private val annotationTypeQualifierResolver: Annotati
                         ?.takeIf { it.annotationClass?.fqNameSafe == JAVAX_NONNULL_ANNOTATION }
                 ?: return null
 
-        return typeQualifier.allValueArguments.values.singleOrNull()?.value?.let {
-            enumEntryDescriptor ->
-            if (enumEntryDescriptor !is ClassDescriptor) return@let null
-            if (enumEntryDescriptor.name.asString() == "ALWAYS") NullabilityQualifier.NOT_NULL else NullabilityQualifier.NULLABLE
-        } ?: NullabilityQualifier.NOT_NULL
+        val enumEntryDescriptor =
+                typeQualifier.allValueArguments.values.singleOrNull()?.value
+                // if no argument is specified, use default value: NOT_NULL
+                ?: return NullabilityQualifier.NOT_NULL
+
+        if (enumEntryDescriptor !is ClassDescriptor) return null
+
+        return when (enumEntryDescriptor.name.asString()) {
+            "ALWAYS" -> NullabilityQualifier.NOT_NULL
+            "MAYBE" -> NullabilityQualifier.NULLABLE
+            else -> null
+        }
     }