diff --git a/gerrit-common/src/main/java/com/google/gerrit/common/data/ReviewerResult.java b/gerrit-common/src/main/java/com/google/gerrit/common/data/ReviewerResult.java
index 678ec79a7e..a535c17357 100644
--- a/gerrit-common/src/main/java/com/google/gerrit/common/data/ReviewerResult.java
+++ b/gerrit-common/src/main/java/com/google/gerrit/common/data/ReviewerResult.java
@@ -56,8 +56,11 @@ public class ReviewerResult {
       /** The account is not permitted to see the change. */
       CHANGE_NOT_VISIBLE,
 
-      /** Could not remove this reviewer from the change. */
-      COULD_NOT_REMOVE
+      /** Could not remove this reviewer from the change due to ORMException. */
+      COULD_NOT_REMOVE,
+
+      /** Not permitted to remove this reviewer from the change. */
+      REMOVE_NOT_PERMITTED
     }
 
     protected Type type;
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ApprovalTable.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ApprovalTable.java
index a20b02ec89..4a5c1ced97 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ApprovalTable.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ApprovalTable.java
@@ -304,7 +304,18 @@ public class ApprovalTable extends Composite {
               final ChangeDetail r = result.getChange();
               display(r.getChange(), r.getMissingApprovals(), r.getApprovals());
             } else {
-              new ErrorDialog(result.getErrors().get(0).toString()).center();
+              final ReviewerResult.Error resultError =
+                  result.getErrors().get(0);
+              String message;
+              switch (resultError.getType()) {
+                case REMOVE_NOT_PERMITTED:
+                  message = Util.C.approvalTableRemoveNotPermitted();
+                  break;
+                case COULD_NOT_REMOVE:
+                default:
+                  message = Util.C.approvalTableCouldNotRemove();
+              }
+              new ErrorDialog(message + " " + resultError.getName()).center();
             }
           }
 
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.java
index e4fe6d2911..0618294ce2 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.java
@@ -78,6 +78,8 @@ public interface ChangeConstants extends Constants {
 
   String approvalTableReviewer();
   String approvalTableAddReviewer();
+  String approvalTableRemoveNotPermitted();
+  String approvalTableCouldNotRemove();
 
   String changeInfoBlockOwner();
   String changeInfoBlockProject();
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.properties b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.properties
index 7032ddae11..e65832dcfe 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.properties
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeConstants.properties
@@ -55,6 +55,8 @@ changeScreenComments = Comments
 
 approvalTableReviewer = Reviewer
 approvalTableAddReviewer = Add Reviewer
+approvalTableRemoveNotPermitted = Not allowed to remove reviewer
+approvalTableCouldNotRemove = Could not remove reviewer
 
 changeInfoBlockOwner = Owner
 changeInfoBlockProject = Project
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/patch/RemoveReviewer.java b/gerrit-server/src/main/java/com/google/gerrit/server/patch/RemoveReviewer.java
index 4e54423009..e1c8c6b7fa 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/patch/RemoveReviewer.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/patch/RemoveReviewer.java
@@ -78,12 +78,12 @@ public class RemoveReviewer implements Callable<ReviewerResult> {
       } catch (OrmException ex) {
         result.addError(new ReviewerResult.Error(
             ReviewerResult.Error.Type.COULD_NOT_REMOVE,
-            "Could not remove reviewer " + reviewerId));
+            reviewerId.toString()));
       }
     } else {
       result.addError(new ReviewerResult.Error(
-          ReviewerResult.Error.Type.COULD_NOT_REMOVE,
-          "Not allowed to remove reviewer " + reviewerId));
+          ReviewerResult.Error.Type.REMOVE_NOT_PERMITTED,
+          reviewerId.toString()));
     }
 
     return result;