diff --git a/src/ExternalResource.ts b/src/ExternalResource.ts
index dba0183..2765622 100644
--- a/src/ExternalResource.ts
+++ b/src/ExternalResource.ts
@@ -53,9 +53,11 @@ export class ExternalResource implements IExternalResource {
       if (!id.endsWith("/")) {
         id += "/";
       }
+
+      const profile = service.getProfile();
       if (
-        service.getProfile() &&
-        (Utils.isImageProfile(service.getProfile()) ||
+        profile &&
+        (Utils.isImageProfile(profile) ||
           Utils.isImageServiceType(service.getIIIFResourceType()))
       ) {
         infoUri = id + "info.json";
@@ -175,22 +177,41 @@ export class ExternalResource implements IExternalResource {
         }
       }
 
-      this.clickThroughService = Utils.getService(
+      const clickThroughService = Utils.getService(
         resource,
         ServiceProfile.AUTH_1_CLICK_THROUGH
       );
-      this.loginService = Utils.getService(
+      if (clickThroughService) {
+        this.clickThroughService = clickThroughService;
+      }
+      const loginService = Utils.getService(
         resource,
         ServiceProfile.AUTH_1_LOGIN
       );
-      this.externalService = Utils.getService(
+      if (loginService) {
+        this.loginService = loginService;
+      }
+      const externalService = Utils.getService(
         resource,
         ServiceProfile.AUTH_1_EXTERNAL
       );
-      this.kioskService = Utils.getService(
+      if (externalService) {
+        this.externalService = externalService;
+      }
+      const kioskService = Utils.getService(
         resource,
         ServiceProfile.AUTH_1_KIOSK
       );
+      if (kioskService) {
+        this.kioskService = kioskService;
+      }
+      const probeService = Utils.getService(
+        resource,
+        ServiceProfile.AUTH_1_PROBE
+      );
+      if (probeService) {
+        this.probeService = probeService;
+      }
 
       if (this.clickThroughService) {
         this.logoutService = this.clickThroughService.getService(
@@ -199,9 +220,11 @@ export class ExternalResource implements IExternalResource {
         this.tokenService = this.clickThroughService.getService(
           ServiceProfile.AUTH_1_TOKEN
         );
-        this.probeService = this.clickThroughService.getService(
-          ServiceProfile.AUTH_1_PROBE
-        );
+        if (!this.probeService) {
+          this.probeService = this.clickThroughService.getService(
+            ServiceProfile.AUTH_1_PROBE
+          );
+        }
       } else if (this.loginService) {
         this.logoutService = this.loginService.getService(
           ServiceProfile.AUTH_1_LOGOUT
@@ -210,10 +233,12 @@ export class ExternalResource implements IExternalResource {
           ServiceProfile.AUTH_1_TOKEN
         );
 
-        this.probeService = Utils.getService(
-          resource,
-          ServiceProfile.AUTH_1_PROBE
-        );
+        if (!this.probeService) {
+          this.probeService = Utils.getService(
+            resource,
+            ServiceProfile.AUTH_1_PROBE
+          );
+        }
 
         // @deprecated - the probe should be on the resource.
         if (!this.probeService) {
@@ -228,10 +253,12 @@ export class ExternalResource implements IExternalResource {
         this.tokenService = this.externalService.getService(
           ServiceProfile.AUTH_1_TOKEN
         );
-        this.probeService = Utils.getService(
-          resource,
-          ServiceProfile.AUTH_1_PROBE
-        );
+        if (!this.probeService) {
+          this.probeService = Utils.getService(
+            resource,
+            ServiceProfile.AUTH_1_PROBE
+          );
+        }
 
         // @deprecated - the probe should be on the resource.
         if (!this.probeService) {
@@ -246,10 +273,12 @@ export class ExternalResource implements IExternalResource {
         this.tokenService = this.kioskService.getService(
           ServiceProfile.AUTH_1_TOKEN
         );
-        this.probeService = Utils.getService(
-          resource,
-          ServiceProfile.AUTH_1_PROBE
-        );
+        if (!this.probeService) {
+          this.probeService = Utils.getService(
+            resource,
+            ServiceProfile.AUTH_1_PROBE
+          );
+        }
 
         // @deprecated - the probe should be on the resource.
         if (!this.probeService) {