diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaVariableValue.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaVariableValue.java
index 76d0be269059..65b5e61b28a7 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaVariableValue.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/value/DfaVariableValue.java
@@ -30,6 +30,7 @@ import com.intellij.codeInspection.dataFlow.DfaPsiUtil;
 import com.intellij.codeInspection.dataFlow.Nullness;
 import com.intellij.openapi.util.Comparing;
 import com.intellij.openapi.util.Trinity;
+import com.intellij.patterns.ElementPattern;
 import com.intellij.psi.*;
 import com.intellij.psi.util.PsiUtil;
 import com.intellij.psi.util.TypeConversionUtil;
@@ -40,8 +41,13 @@ import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
+import static com.intellij.patterns.PsiJavaPatterns.*;
+
 public class DfaVariableValue extends DfaValue {
 
+  private static final ElementPattern<? extends PsiModifierListOwner> MEMBER_OR_METHOD_PARAMETER =
+    or(psiMember(), psiParameter().withSuperParent(2, psiMember()));
+
   public static class Factory {
     private final MultiMap<Trinity<Boolean,String,DfaVariableValue>,DfaVariableValue> myExistingVars = new MultiMap<Trinity<Boolean, String, DfaVariableValue>, DfaVariableValue>();
     private final DfaValueFactory myFactory;
@@ -165,7 +171,7 @@ public class DfaVariableValue extends DfaValue {
       return nullability;
     }
 
-    Nullness defaultNullability = var instanceof PsiMember && myFactory.isUnknownMembersAreNullable() ? Nullness.NULLABLE : Nullness.UNKNOWN;
+    Nullness defaultNullability = myFactory.isUnknownMembersAreNullable() && MEMBER_OR_METHOD_PARAMETER.accepts(var) ? Nullness.NULLABLE : Nullness.UNKNOWN;
 
     if (var instanceof PsiParameter && var.getParent() instanceof PsiForeachStatement) {
       PsiExpression iteratedValue = ((PsiForeachStatement)var.getParent()).getIteratedValue();
diff --git a/java/java-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspection.java b/java/java-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspection.java
index e383b6a4e89a..d7ec7920d09b 100644
--- a/java/java-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspection.java
+++ b/java/java-impl/src/com/intellij/codeInspection/dataFlow/DataFlowInspection.java
@@ -117,7 +117,7 @@ public class DataFlowInspection extends DataFlowInspectionBase {
         }
       });
 
-      myTreatUnknownMembersAsNullable = new JCheckBox("Treat non-annotated methods and fields as @Nullable");
+      myTreatUnknownMembersAsNullable = new JCheckBox("Treat non-annotated members and parameters as @Nullable");
       myTreatUnknownMembersAsNullable.setSelected(TREAT_UNKNOWN_MEMBERS_AS_NULLABLE);
       myTreatUnknownMembersAsNullable.getModel().addChangeListener(new ChangeListener() {
         @Override
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/ParanoidMode.java b/java/java-tests/testData/inspection/dataFlow/fixture/ParanoidMode.java
index 96448a4d0d95..792d7a1de5b7 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/ParanoidMode.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/ParanoidMode.java
@@ -7,6 +7,10 @@ class Test {
     <warning descr="Method invocation 'o.hashCode()' may produce 'java.lang.NullPointerException'">o.hashCode()</warning>;
   }
 
+  void parameter(Object o) {
+    <warning descr="Method invocation 'o.hashCode()' may produce 'java.lang.NullPointerException'">o.hashCode()</warning>;
+  }
+
   void callUnknownMethod() {
     <warning descr="Method invocation 'unknownObject().hashCode()' may produce 'java.lang.NullPointerException'">unknownObject().hashCode()</warning>;
   }