diff --git a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/DecisionMapper.java b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/DecisionMapper.java
index 518367d37..b74754257 100644
--- a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/DecisionMapper.java
+++ b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/DecisionMapper.java
@@ -157,7 +157,7 @@ static Decision decision(com.uber.cadence.Decision d) {
               d.getRequestCancelExternalWorkflowExecutionDecisionAttributes();
           RequestCancelExternalWorkflowExecutionDecisionAttributes.Builder builder =
               RequestCancelExternalWorkflowExecutionDecisionAttributes.newBuilder()
-                  .setDomain(attr.getDomain())
+                  .setDomain(attr.getDomain() != null ? attr.getDomain() : "")
                   .setWorkflowExecution(workflowRunPair(attr.getWorkflowId(), attr.getRunId()))
                   .setChildWorkflowOnly(attr.isChildWorkflowOnly());
           if (attr.getControl() != null) {
@@ -202,7 +202,7 @@ static Decision decision(com.uber.cadence.Decision d) {
               d.getStartChildWorkflowExecutionDecisionAttributes();
           StartChildWorkflowExecutionDecisionAttributes.Builder builder =
               StartChildWorkflowExecutionDecisionAttributes.newBuilder()
-                  .setDomain(attr.getDomain())
+                  .setDomain(attr.getDomain() != null ? attr.getDomain() : "")
                   .setWorkflowId(attr.getWorkflowId())
                   .setWorkflowType(workflowType(attr.getWorkflowType()))
                   .setTaskList(taskList(attr.getTaskList()))
@@ -234,7 +234,7 @@ static Decision decision(com.uber.cadence.Decision d) {
               d.getSignalExternalWorkflowExecutionDecisionAttributes();
           SignalExternalWorkflowExecutionDecisionAttributes.Builder builder =
               SignalExternalWorkflowExecutionDecisionAttributes.newBuilder()
-                  .setDomain(attr.getDomain())
+                  .setDomain(attr.getDomain() != null ? attr.getDomain() : "")
                   .setWorkflowExecution(workflowExecution(attr.getExecution()))
                   .setSignalName(attr.getSignalName())
                   .setInput(payload(attr.getInput()))
diff --git a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/RequestMapper.java b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/RequestMapper.java
index 818b97685..f1ba7c823 100644
--- a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/RequestMapper.java
+++ b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/RequestMapper.java
@@ -121,7 +121,8 @@ public static CountWorkflowExecutionsRequest countWorkflowExecutionsRequest(
       return null;
     }
     CountWorkflowExecutionsRequest.Builder request =
-        CountWorkflowExecutionsRequest.newBuilder().setDomain(t.getDomain());
+        CountWorkflowExecutionsRequest.newBuilder()
+            .setDomain(t.getDomain() != null ? t.getDomain() : "");
     if (t.getQuery() != null) {
       request.setQuery(t.getQuery());
     }
@@ -134,7 +135,7 @@ public static DescribeTaskListRequest describeTaskListRequest(
       return null;
     }
     return DescribeTaskListRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setTaskList(taskList(t.getTaskList()))
         .setTaskListType(taskListType(t.getTaskListType()))
         .setIncludeTaskListStatus(t.isIncludeTaskListStatus())
@@ -148,7 +149,7 @@ public static ListArchivedWorkflowExecutionsRequest listArchivedWorkflowExecutio
     }
     ListArchivedWorkflowExecutionsRequest.Builder request =
         ListArchivedWorkflowExecutionsRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setPageSize(t.getPageSize());
     if (t.getNextPageToken() != null) {
       request.setNextPageToken(arrayToByteString(t.getNextPageToken()));
@@ -166,7 +167,7 @@ public static RequestCancelWorkflowExecutionRequest requestCancelWorkflowExecuti
     }
     RequestCancelWorkflowExecutionRequest.Builder builder =
         RequestCancelWorkflowExecutionRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(workflowExecution(t.getWorkflowExecution()))
             .setRequestId(t.getRequestId());
     if (t.getIdentity() != null) {
@@ -187,7 +188,7 @@ public static ResetStickyTaskListRequest resetStickyTaskListRequest(
       return null;
     }
     return ResetStickyTaskListRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setWorkflowExecution(workflowExecution(t.getExecution()))
         .build();
   }
@@ -198,7 +199,7 @@ public static ResetWorkflowExecutionRequest resetWorkflowExecutionRequest(
       return null;
     }
     return ResetWorkflowExecutionRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setWorkflowExecution(workflowExecution(t.getWorkflowExecution()))
         .setReason(t.getReason() != null ? t.getReason() : "")
         .setDecisionFinishEventId(t.getDecisionFinishEventId())
@@ -214,7 +215,7 @@ public static RespondActivityTaskCanceledByIDRequest respondActivityTaskCanceled
     }
     RespondActivityTaskCanceledByIDRequest.Builder builder =
         RespondActivityTaskCanceledByIDRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(TypeMapper.workflowRunPair(t.getWorkflowID(), t.getRunID()))
             .setActivityId(t.getActivityID())
             .setDetails(payload(t.getDetails()));
@@ -247,7 +248,7 @@ public static RespondActivityTaskCompletedByIDRequest respondActivityTaskComplet
     }
     RespondActivityTaskCompletedByIDRequest.Builder builder =
         RespondActivityTaskCompletedByIDRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(TypeMapper.workflowRunPair(t.getWorkflowID(), t.getRunID()))
             .setActivityId(t.getActivityID())
             .setResult(payload(t.getResult()));
@@ -280,7 +281,7 @@ public static RespondActivityTaskFailedByIDRequest respondActivityTaskFailedById
     }
     RespondActivityTaskFailedByIDRequest.Builder builder =
         RespondActivityTaskFailedByIDRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(TypeMapper.workflowRunPair(t.getWorkflowID(), t.getRunID()))
             .setActivityId(t.getActivityID())
             .setFailure(failure(t.getReason(), t.getDetails()));
@@ -384,7 +385,7 @@ public static ScanWorkflowExecutionsRequest scanWorkflowExecutionsRequest(
     }
     ScanWorkflowExecutionsRequest.Builder request =
         ScanWorkflowExecutionsRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setPageSize(t.getPageSize());
     if (t.getNextPageToken() != null) {
       request.setNextPageToken(arrayToByteString(t.getNextPageToken()));
@@ -401,7 +402,7 @@ public static DescribeWorkflowExecutionRequest describeWorkflowExecutionRequest(
       return null;
     }
     return DescribeWorkflowExecutionRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setWorkflowExecution(workflowExecution(t.getExecution()))
         .setQueryConsistencyLevel(queryConsistencyLevel(t.getQueryConsistencyLevel()))
         .build();
@@ -414,7 +415,7 @@ public static GetWorkflowExecutionHistoryRequest getWorkflowExecutionHistoryRequ
     }
     GetWorkflowExecutionHistoryRequest.Builder builder =
         GetWorkflowExecutionHistoryRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(workflowExecution(t.getExecution()))
             .setPageSize(t.getMaximumPageSize())
             .setWaitForNewEvent(t.isWaitForNewEvent())
@@ -434,7 +435,7 @@ public static SignalWithStartWorkflowExecutionRequest signalWithStartWorkflowExe
     }
     StartWorkflowExecutionRequest.Builder builder =
         StartWorkflowExecutionRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowId(t.getWorkflowId())
             .setWorkflowType(workflowType(t.getWorkflowType()))
             .setTaskList(taskList(t.getTaskList()))
@@ -497,7 +498,7 @@ public static SignalWorkflowExecutionRequest signalWorkflowExecutionRequest(
     }
     SignalWorkflowExecutionRequest.Builder builder =
         SignalWorkflowExecutionRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(workflowExecution(t.getWorkflowExecution()))
             .setSignalName(t.getSignalName())
             .setSignalInput(payload(t.getInput()))
@@ -518,7 +519,7 @@ public static StartWorkflowExecutionRequest startWorkflowExecutionRequest(
     }
     StartWorkflowExecutionRequest.Builder request =
         StartWorkflowExecutionRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowId(t.getWorkflowId())
             .setWorkflowType(workflowType(t.getWorkflowType()))
             .setTaskList(taskList(t.getTaskList()))
@@ -566,7 +567,7 @@ public static TerminateWorkflowExecutionRequest terminateWorkflowExecutionReques
     }
     TerminateWorkflowExecutionRequest.Builder builder =
         TerminateWorkflowExecutionRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(workflowExecution(t.getWorkflowExecution()))
             .setReason(t.getReason() != null ? t.getReason() : "")
             .setDetails(payload(t.getDetails()));
@@ -622,7 +623,7 @@ public static ListTaskListPartitionsRequest listTaskListPartitionsRequest(
       return null;
     }
     return ListTaskListPartitionsRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setTaskList(taskList(t.getTaskList()))
         .build();
   }
@@ -634,7 +635,7 @@ public static ListWorkflowExecutionsRequest listWorkflowExecutionsRequest(
     }
     ListWorkflowExecutionsRequest.Builder request =
         ListWorkflowExecutionsRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setPageSize(t.getPageSize());
     if (t.getNextPageToken() != null) {
       request.setNextPageToken(arrayToByteString(t.getNextPageToken()));
@@ -652,7 +653,7 @@ public static PollForActivityTaskRequest pollForActivityTaskRequest(
     }
     PollForActivityTaskRequest.Builder builder =
         PollForActivityTaskRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setTaskList(taskList(t.getTaskList()))
             .setTaskListMetadata(taskListMetadata(t.getTaskListMetadata()));
     if (t.getIdentity() != null) {
@@ -668,7 +669,7 @@ public static PollForDecisionTaskRequest pollForDecisionTaskRequest(
     }
     PollForDecisionTaskRequest.Builder builder =
         PollForDecisionTaskRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setTaskList(taskList(t.getTaskList()));
     if (t.getBinaryChecksum() != null) {
       builder.setBinaryChecksum(t.getBinaryChecksum());
@@ -684,7 +685,7 @@ public static QueryWorkflowRequest queryWorkflowRequest(com.uber.cadence.QueryWo
       return null;
     }
     return QueryWorkflowRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setWorkflowExecution(workflowExecution(t.getExecution()))
         .setQuery(workflowQuery(t.getQuery()))
         .setQueryRejectCondition(queryRejectCondition(t.getQueryRejectCondition()))
@@ -699,7 +700,7 @@ public static RecordActivityTaskHeartbeatByIDRequest recordActivityTaskHeartbeat
     }
     RecordActivityTaskHeartbeatByIDRequest.Builder builder =
         RecordActivityTaskHeartbeatByIDRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setWorkflowExecution(TypeMapper.workflowRunPair(t.getWorkflowID(), t.getRunID()))
             .setActivityId(t.getActivityID())
             .setDetails(payload(t.getDetails()));
@@ -756,7 +757,7 @@ public static RestartWorkflowExecutionRequest restartWorkflowExecutionRequest(
       return null;
     }
     return RestartWorkflowExecutionRequest.newBuilder()
-        .setDomain(t.getDomain())
+        .setDomain(t.getDomain() != null ? t.getDomain() : "")
         .setWorkflowExecution(workflowExecution(t.getWorkflowExecution()))
         .setReason(t.getReason() != null ? t.getReason() : "")
         .setIdentity(t.getIdentity() != null ? t.getIdentity() : "")
@@ -852,7 +853,7 @@ public static ListClosedWorkflowExecutionsRequest listClosedWorkflowExecutionsRe
     }
     ListClosedWorkflowExecutionsRequest.Builder request =
         ListClosedWorkflowExecutionsRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setPageSize(t.getMaximumPageSize());
     if (t.getExecutionFilter() != null) {
       request.setExecutionFilter(workflowExecutionFilter(t.getExecutionFilter()));
@@ -879,7 +880,7 @@ public static ListOpenWorkflowExecutionsRequest listOpenWorkflowExecutionsReques
     }
     ListOpenWorkflowExecutionsRequest.Builder request =
         ListOpenWorkflowExecutionsRequest.newBuilder()
-            .setDomain(t.getDomain())
+            .setDomain(t.getDomain() != null ? t.getDomain() : "")
             .setPageSize(t.getMaximumPageSize());
     if (t.getExecutionFilter() != null) {
       request.setExecutionFilter(workflowExecutionFilter(t.getExecutionFilter()));
@@ -903,7 +904,7 @@ public static RespondActivityTaskFailedByIDRequest respondActivityTaskFailedByID
     }
     RespondActivityTaskFailedByIDRequest.Builder request =
         RespondActivityTaskFailedByIDRequest.newBuilder()
-            .setDomain(failRequest.getDomain())
+            .setDomain(failRequest.getDomain() != null ? failRequest.getDomain() : "")
             .setWorkflowExecution(
                 TypeMapper.workflowRunPair(failRequest.getWorkflowID(), failRequest.getRunID()))
             .setActivityId(failRequest.getActivityID())
@@ -919,7 +920,7 @@ public static RespondActivityTaskCompletedByIDRequest respondActivityTaskComplet
     }
     RespondActivityTaskCompletedByIDRequest.Builder request =
         RespondActivityTaskCompletedByIDRequest.newBuilder()
-            .setDomain(completeRequest.getDomain())
+            .setDomain(completeRequest.getDomain() != null ? completeRequest.getDomain() : "")
             .setWorkflowExecution(
                 TypeMapper.workflowRunPair(
                     completeRequest.getWorkflowID(), completeRequest.getRunID()))
@@ -937,7 +938,7 @@ public static RecordActivityTaskHeartbeatByIDRequest recordActivityTaskHeartbeat
     }
     RecordActivityTaskHeartbeatByIDRequest.Builder request =
         RecordActivityTaskHeartbeatByIDRequest.newBuilder()
-            .setDomain(heartbeatRequest.getDomain())
+            .setDomain(heartbeatRequest.getDomain() != null ? heartbeatRequest.getDomain() : "")
             .setWorkflowExecution(
                 TypeMapper.workflowRunPair(
                     heartbeatRequest.getWorkflowID(), heartbeatRequest.getRunID()))
@@ -955,7 +956,7 @@ public static RespondActivityTaskCanceledByIDRequest respondActivityTaskCanceled
     }
     RespondActivityTaskCanceledByIDRequest.Builder request =
         RespondActivityTaskCanceledByIDRequest.newBuilder()
-            .setDomain(canceledRequest.getDomain())
+            .setDomain(canceledRequest.getDomain() != null ? canceledRequest.getDomain() : "")
             .setWorkflowExecution(
                 TypeMapper.workflowRunPair(
                     canceledRequest.getWorkflowID(), canceledRequest.getRunID()))
@@ -972,7 +973,8 @@ public static GetTaskListsByDomainRequest getTaskListsByDomainRequest(
       return null;
     }
     GetTaskListsByDomainRequest.Builder request =
-        GetTaskListsByDomainRequest.newBuilder().setDomain(domainRequest.getDomainName());
+        GetTaskListsByDomainRequest.newBuilder()
+            .setDomain(domainRequest.getDomainName() != null ? domainRequest.getDomainName() : "");
     return request.build();
   }
 
@@ -981,6 +983,8 @@ public static RefreshWorkflowTasksRequest refreshWorkflowTasksRequest(
     if (request == null) {
       return null;
     }
-    return RefreshWorkflowTasksRequest.newBuilder().setDomain(request.getDomain()).build();
+    return RefreshWorkflowTasksRequest.newBuilder()
+        .setDomain(request.getDomain() != null ? request.getDomain() : "")
+        .build();
   }
 }
diff --git a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/TypeMapper.java b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/TypeMapper.java
index 628ba2df3..678d9f080 100644
--- a/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/TypeMapper.java
+++ b/src/main/java/com/uber/cadence/internal/compatibility/proto/mappers/TypeMapper.java
@@ -128,7 +128,10 @@ static WorkflowExecution workflowRunPair(String workflowId, String runId) {
     if (Strings.isNullOrEmpty(workflowId) && Strings.isNullOrEmpty(runId)) {
       return WorkflowExecution.newBuilder().build();
     }
-    return WorkflowExecution.newBuilder().setWorkflowId(workflowId).setRunId(runId).build();
+    return WorkflowExecution.newBuilder()
+        .setWorkflowId(workflowId)
+        .setRunId(runId != null ? runId : "")
+        .build();
   }
 
   static ActivityType activityType(com.uber.cadence.ActivityType t) {
@@ -275,7 +278,7 @@ static WorkflowExecutionFilter workflowExecutionFilter(
     }
     return WorkflowExecutionFilter.newBuilder()
         .setWorkflowId(t.getWorkflowId())
-        .setRunId(t.getRunId())
+        .setRunId(t.getRunId() != null ? t.getRunId() : "")
         .build();
   }