diff --git a/src/main/java/com/smartystreets/api/SmartySender.java b/src/main/java/com/smartystreets/api/SmartySender.java
index 1acc127..d215c90 100644
--- a/src/main/java/com/smartystreets/api/SmartySender.java
+++ b/src/main/java/com/smartystreets/api/SmartySender.java
@@ -8,6 +8,7 @@
 import java.io.IOException;
 import java.net.Proxy;
 import java.util.Map;
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.logging.Handler;
 import java.util.logging.Level;
@@ -61,7 +62,7 @@ private okhttp3.Request buildHttpRequest(Request smartyRequest) throws IOExcepti
         Map<String, Object> headers = smartyRequest.getHeaders();
         Headers.Builder headersBuilder = new Headers.Builder();
         for (String headerName : headers.keySet()) {
-            headersBuilder.add(headerName, headers.get(headerName).toString());
+            headersBuilder.add(headerName, Optional.ofNullable(headers.get(headerName)).orElse("").toString());
         }
 
         okhttp3.Request.Builder requestBuilder = new okhttp3.Request.Builder()
diff --git a/src/main/java/com/smartystreets/api/us_street/Lookup.java b/src/main/java/com/smartystreets/api/us_street/Lookup.java
index e59e42a..c4e7370 100644
--- a/src/main/java/com/smartystreets/api/us_street/Lookup.java
+++ b/src/main/java/com/smartystreets/api/us_street/Lookup.java
@@ -135,10 +135,14 @@ public String getMatch() {
         return null;
     }
 
+    /**
+     * This is a temporary flag meant to fix an intermittent data issue
+     * Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+     *
+     * @deprecated - Temporary - will be removed in a future release.
+     */
     @JsonProperty("compatibility")
     public String getCompatibility() {
-        //This is a temporary flag meant to fix an intermittent data issue
-        //Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
         return this.compatibility;
     }
 
@@ -214,9 +218,13 @@ public void setUrbanization(String urbanization) {
         this.urbanization = urbanization;
     }
 
+    /**
+     * This is a temporary flag meant to fix an intermittent data issue
+     * Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+     *
+     * @deprecated - Temporary - will be removed in a future release.
+     */
     public void setCompatibility(String compatibility) {
-        //This is a temporary flag meant to fix an intermittent data issue
-        //Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
         this.compatibility = compatibility;
     }
     /**
diff --git a/src/main/java/com/smartystreets/api/us_zipcode/Client.java b/src/main/java/com/smartystreets/api/us_zipcode/Client.java
index c46cb24..ff716c0 100644
--- a/src/main/java/com/smartystreets/api/us_zipcode/Client.java
+++ b/src/main/java/com/smartystreets/api/us_zipcode/Client.java
@@ -57,6 +57,9 @@ private void populateQueryString(Lookup lookup, Request request) {
         request.putParameter("city", lookup.getCity());
         request.putParameter("state", lookup.getState());
         request.putParameter("zipcode", lookup.getZipCode());
+        //This is a temporary flag meant to fix an intermittent data issue
+        //Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+        request.putParameter("compatibility", lookup.getCompatibility());
     }
 
 
diff --git a/src/main/java/com/smartystreets/api/us_zipcode/Lookup.java b/src/main/java/com/smartystreets/api/us_zipcode/Lookup.java
index d15ce43..5e73ffd 100644
--- a/src/main/java/com/smartystreets/api/us_zipcode/Lookup.java
+++ b/src/main/java/com/smartystreets/api/us_zipcode/Lookup.java
@@ -20,6 +20,11 @@ public class Lookup implements Serializable {
     private String state;
     private String zipcode;
 
+    //This is a temporary flag meant to fix an intermittent data issue
+    //Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+    private String compatibility;
+
+
     //endregion
 
     public Lookup() {
@@ -67,6 +72,16 @@ public String getInputId() {
         return this.inputId;
     }
 
+    /**
+     * This is a temporary flag meant to fix an intermittent data issue
+     * Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+     *
+     * @deprecated - Temporary - will be removed in a future release.
+     */
+    public String getCompatibility() {
+        return this.compatibility;
+    }
+
     //endregion
 
     //region [ Setters ]
@@ -91,6 +106,16 @@ public void setZipCode(String zipcode) {
         this.zipcode = zipcode;
     }
 
+    /**
+     * This is a temporary flag meant to fix an intermittent data issue
+     * Unless explicitly instructed by the Smarty Tech Support team, DO NOT use this parameter
+     *
+     * * @deprecated - Temporary - will be removed in a future release.
+     */
+    public void setCompatibility(String compatibility) {
+        this.compatibility = compatibility;
+    }
+
     public Lookup setInputId(String inputId) {
         this.inputId = inputId;
         return this;