diff --git a/src/com/android/phone/PhoneInterfaceManager.java b/src/com/android/phone/PhoneInterfaceManager.java
index 011d041..991ebdd 100644
--- a/src/com/android/phone/PhoneInterfaceManager.java
+++ b/src/com/android/phone/PhoneInterfaceManager.java
@@ -4387,7 +4387,18 @@
         try {
             int slotId = getSlotIndexOrException(subId);
             verifyImsMmTelConfiguredOrThrow(slotId);
-            ImsManager.getInstance(mApp, slotId).addCapabilitiesCallbackForSubscription(c, subId);
+
+            ImsStateCallbackController controller = ImsStateCallbackController.getInstance();
+            if (controller != null) {
+                ImsManager imsManager = controller.getImsManager(subId);
+                if (imsManager != null) {
+                    imsManager.addCapabilitiesCallbackForSubscription(c, subId);
+                } else {
+                    throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE);
+                }
+            } else {
+                throw new ServiceSpecificException(ImsException.CODE_ERROR_UNSUPPORTED_OPERATION);
+            }
         } catch (ImsException e) {
             throw new ServiceSpecificException(e.getCode());
         } finally {
@@ -4410,13 +4421,18 @@
 
         final long token = Binder.clearCallingIdentity();
         try {
-            ImsManager.getInstance(mApp, getSlotIndexOrException(subId))
-                        .removeCapabilitiesCallbackForSubscription(c, subId);
-        } catch (ImsException e) {
-            Log.i(LOG_TAG, "unregisterMmTelCapabilityCallback: " + subId
-                     + "is inactive, ignoring unregister.");
-             // If the subscription is no longer active, just return, since the callback
-             // will already have been removed internally.
+            ImsStateCallbackController controller = ImsStateCallbackController.getInstance();
+            if (controller != null) {
+                ImsManager imsManager = controller.getImsManager(subId);
+                if (imsManager != null) {
+                    imsManager.removeCapabilitiesCallbackForSubscription(c, subId);
+                } else {
+                    Log.i(LOG_TAG, "unregisterMmTelCapabilityCallback: " + subId
+                            + " is inactive, ignoring unregister.");
+                    // If the ImsManager is not valid, just return, since the callback
+                    // will already have been removed internally.
+                }
+            }
         } finally {
             Binder.restoreCallingIdentity(token);
         }
@@ -4827,8 +4843,18 @@
             }
             int slotId = getSlotIndexOrException(subId);
             verifyImsMmTelConfiguredOrThrow(slotId);
-            ImsManager.getInstance(mApp, slotId)
-                    .addProvisioningCallbackForSubscription(callback, subId);
+
+            ImsStateCallbackController controller = ImsStateCallbackController.getInstance();
+            if (controller != null) {
+                ImsManager imsManager = controller.getImsManager(subId);
+                if (imsManager != null) {
+                    imsManager.addProvisioningCallbackForSubscription(callback, subId);
+                } else {
+                    throw new ServiceSpecificException(ImsException.CODE_ERROR_SERVICE_UNAVAILABLE);
+                }
+            } else {
+                throw new ServiceSpecificException(ImsException.CODE_ERROR_UNSUPPORTED_OPERATION);
+            }
         } catch (ImsException e) {
             throw new ServiceSpecificException(e.getCode());
         } finally {
@@ -4845,13 +4871,18 @@
             throw new IllegalArgumentException("Invalid Subscription ID: " + subId);
         }
         try {
-            ImsManager.getInstance(mApp, getSlotIndexOrException(subId))
-                    .removeProvisioningCallbackForSubscription(callback, subId);
-        } catch (ImsException e) {
-            Log.i(LOG_TAG, "unregisterImsProvisioningChangedCallback: " + subId
-                    + "is inactive, ignoring unregister.");
-            // If the subscription is no longer active, just return, since the callback will already
-            // have been removed internally.
+            ImsStateCallbackController controller = ImsStateCallbackController.getInstance();
+            if (controller != null) {
+                ImsManager imsManager = controller.getImsManager(subId);
+                if (imsManager != null) {
+                    imsManager.removeProvisioningCallbackForSubscription(callback, subId);
+                } else {
+                    Log.i(LOG_TAG, "unregisterImsProvisioningChangedCallback: " + subId
+                            + " is inactive, ignoring unregister.");
+                    // If the ImsManager is not valid, just return, since the callback will already
+                    // have been removed internally.
+                }
+            }
         } finally {
             Binder.restoreCallingIdentity(identity);
         }