diff --git a/zuul-core/src/main/java/com/netflix/zuul/message/http/HttpRequestMessageImpl.java b/zuul-core/src/main/java/com/netflix/zuul/message/http/HttpRequestMessageImpl.java
index 4cc24192dc..8f56a7f784 100644
--- a/zuul-core/src/main/java/com/netflix/zuul/message/http/HttpRequestMessageImpl.java
+++ b/zuul-core/src/main/java/com/netflix/zuul/message/http/HttpRequestMessageImpl.java
@@ -97,6 +97,7 @@ public class HttpRequestMessageImpl implements HttpRequestMessage {
     private String reconstructedUri = null;
     private String pathAndQuery = null;
     private String infoForLogging = null;
+    private String originalHost = null;
 
     private static final SocketAddress UNDEFINED_CLIENT_DEST_ADDRESS = new SocketAddress() {
         @Override
@@ -510,7 +511,10 @@ protected String generateInfoForLogging() {
     @Override
     public String getOriginalHost() {
         try {
-            return getOriginalHost(getHeaders(), getServerName());
+            if (originalHost == null) {
+                originalHost = getOriginalHost(getHeaders(), getServerName());
+            }
+            return originalHost;
         } catch (URISyntaxException e) {
             throw new IllegalArgumentException(e);
         }
@@ -662,7 +666,7 @@ protected String _reconstructURI() {
 
             String scheme = getOriginalScheme().toLowerCase();
             uri.append(scheme);
-            uri.append(URI_SCHEME_SEP).append(getOriginalHost(getHeaders(), getServerName()));
+            uri.append(URI_SCHEME_SEP).append(getOriginalHost());
 
             int port = getOriginalPort();
             if ((URI_SCHEME_HTTP.equals(scheme) && 80 == port) || (URI_SCHEME_HTTPS.equals(scheme) && 443 == port)) {
@@ -674,7 +678,7 @@ protected String _reconstructURI() {
             uri.append(getPathAndQuery());
 
             return uri.toString();
-        } catch (URISyntaxException e) {
+        } catch (IllegalArgumentException e) {
             // This is not really so bad, just debug log it and move on.
             LOG.debug("Error reconstructing request URI!", e);
             return "";
@@ -700,7 +704,8 @@ public String toString() {
                 + inboundRequest + ", parsedCookies="
                 + parsedCookies + ", reconstructedUri='"
                 + reconstructedUri + '\'' + ", pathAndQuery='"
-                + pathAndQuery + '\'' + ", infoForLogging='"
+                + pathAndQuery + '\'' + "/ originalHost='"
+                + originalHost + '\'' + ", infoForLogging='"
                 + infoForLogging + '\'' + '}';
     }
 }
diff --git a/zuul-core/src/test/java/com/netflix/zuul/message/http/HttpRequestMessageImplTest.java b/zuul-core/src/test/java/com/netflix/zuul/message/http/HttpRequestMessageImplTest.java
index e35dfec51b..2e2419a224 100644
--- a/zuul-core/src/test/java/com/netflix/zuul/message/http/HttpRequestMessageImplTest.java
+++ b/zuul-core/src/test/java/com/netflix/zuul/message/http/HttpRequestMessageImplTest.java
@@ -305,6 +305,34 @@ void testPathAndQuery_immutable() {
         assertEquals("/blah", request.getPathAndQuery());
     }
 
+    @Test
+    void testGetOriginalHost_immutable() {
+        HttpQueryParams queryParams = new HttpQueryParams();
+        Headers headers = new Headers();
+        headers.add("Host", "blah.netflix.com");
+        request = new HttpRequestMessageImpl(
+                new SessionContext(),
+                "HTTP/1.1",
+                "POST",
+                "/some/where",
+                queryParams,
+                headers,
+                "192.168.0.2",
+                "https",
+                7002,
+                "localhost",
+                new SocketAddress() {},
+                true);
+
+        // Check it's the same value 2nd time.
+        assertEquals("blah.netflix.com", request.getOriginalHost());
+        assertEquals("blah.netflix.com", request.getOriginalHost());
+
+        // Update the Host header value and ensure the result didn't change.
+        headers.set("Host", "testOriginalHost2");
+        assertEquals("blah.netflix.com", request.getOriginalHost());
+    }
+
     @Test
     void testGetOriginalHost() {
         HttpQueryParams queryParams = new HttpQueryParams();