diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/BasicCallResolutionContext.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/BasicCallResolutionContext.java
index a68985326ce..d185d34f5e9 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/BasicCallResolutionContext.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/BasicCallResolutionContext.java
@@ -94,6 +94,7 @@ public class BasicCallResolutionContext extends CallResolutionContext<BasicCallR
                 dataFlowInfoForArguments, callResolverExtension, isAnnotationContext, collectAllCandidates);
     }
 
+    @NotNull
     public BasicCallResolutionContext replaceCall(@NotNull Call newCall) {
         return new BasicCallResolutionContext(
                 trace, scope, newCall, expectedType, dataFlowInfo, contextDependency, checkArguments, resolutionResultsCache,
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallCandidateResolutionContext.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallCandidateResolutionContext.java
index bc338551c24..889ff52c999 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallCandidateResolutionContext.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallCandidateResolutionContext.java
@@ -31,8 +31,11 @@ import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
 import org.jetbrains.jet.lang.types.JetType;
 
 public final class CallCandidateResolutionContext<D extends CallableDescriptor> extends CallResolutionContext<CallCandidateResolutionContext<D>> {
+    @NotNull
     public final MutableResolvedCall<D> candidateCall;
+    @NotNull
     public final TracingStrategy tracing;
+    @NotNull
     public final ReceiverValue explicitExtensionReceiverForInvoke;
 
     private CallCandidateResolutionContext(
@@ -84,6 +87,7 @@ public final class CallCandidateResolutionContext<D extends CallableDescriptor>
         return create(candidateCall, context, trace, tracing, context.call);
     }
 
+    @NotNull
     public static <D extends CallableDescriptor> CallCandidateResolutionContext<D> createForCallBeingAnalyzed(
             @NotNull MutableResolvedCall<D> candidateCall, @NotNull BasicCallResolutionContext context, @NotNull TracingStrategy tracing
     ) {
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallResolutionContext.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallResolutionContext.java
index 76edb9305fb..c0101f7a90c 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallResolutionContext.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/CallResolutionContext.java
@@ -28,7 +28,9 @@ import org.jetbrains.jet.lang.resolve.scopes.JetScope;
 import org.jetbrains.jet.lang.types.JetType;
 
 public abstract class CallResolutionContext<Context extends CallResolutionContext<Context>> extends ResolutionContext<Context> {
+    @NotNull
     public final Call call;
+    @NotNull
     public final CheckValueArgumentsMode checkArguments;
     @NotNull
     public final MutableDataFlowInfoForArguments dataFlowInfoForArguments;
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/ResolutionContext.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/ResolutionContext.java
index cd46d4c775f..5ccfebfa138 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/ResolutionContext.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/context/ResolutionContext.java
@@ -26,14 +26,23 @@ import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.TypeUtils;
 
 public abstract class ResolutionContext<Context extends ResolutionContext<Context>> {
+    @NotNull
     public final BindingTrace trace;
+    @NotNull
     public final JetScope scope;
+    @NotNull
     public final JetType expectedType;
+    @NotNull
     public final DataFlowInfo dataFlowInfo;
+    @NotNull
     public final ContextDependency contextDependency;
+    @NotNull
     public final ResolutionResultsCache resolutionResultsCache;
+    @NotNull
     public final CallResolverExtension callResolverExtension;
+
     public final boolean isAnnotationContext;
+
     public final boolean collectAllCandidates;
 
     protected ResolutionContext(
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/InferenceErrorData.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/InferenceErrorData.java
index 8651552688d..b3d76b2c2b4 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/InferenceErrorData.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/inference/InferenceErrorData.java
@@ -47,6 +47,7 @@ public class InferenceErrorData {
         this.expectedType = expectedType;
     }
 
+    @NotNull
     public static InferenceErrorData create(@NotNull CallableDescriptor descriptor, @NotNull ConstraintSystem constraintSystem,
             @NotNull List<JetType> valueArgumentsTypes, @Nullable JetType receiverArgumentType, @NotNull JetType expectedType) {
         return new InferenceErrorData(descriptor, constraintSystem, valueArgumentsTypes, receiverArgumentType, expectedType);
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/results/OverloadResolutionResultsImpl.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/results/OverloadResolutionResultsImpl.java
index bc775e90d2b..929de9b7da5 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/results/OverloadResolutionResultsImpl.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/results/OverloadResolutionResultsImpl.java
@@ -141,6 +141,7 @@ public class OverloadResolutionResultsImpl<D extends CallableDescriptor> impleme
         return allCandidates;
     }
 
+    @NotNull
     public OverloadResolutionResultsImpl<D> changeStatusToSuccess() {
         if (getResultCode() == Code.SUCCESS) return this;
 
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystem.java b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystem.java
index d10d9ead394..610718c8be5 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystem.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/resolve/calls/inference/ConstraintSystem.java
@@ -86,5 +86,6 @@ public interface ConstraintSystem {
     @NotNull
     TypeSubstitutor getCurrentSubstitutor();
 
+    @NotNull
     ConstraintSystem copy();
 }