diff --git a/sources/MVCFramework.RESTAdapter.pas b/sources/MVCFramework.RESTAdapter.pas
index 297152ec..69c85df0 100644
--- a/sources/MVCFramework.RESTAdapter.pas
+++ b/sources/MVCFramework.RESTAdapter.pas
@@ -272,7 +272,7 @@ begin
       lResp := fRESTClient.Head(lURL);
     else
     begin
-      raise Exception.Create('Error Message');
+      raise Exception.Create('Invalid HTTP method');
     end;
   end;
 
diff --git a/sources/MVCFramework.pas b/sources/MVCFramework.pas
index 0e570f52..c6684526 100644
--- a/sources/MVCFramework.pas
+++ b/sources/MVCFramework.pas
@@ -3984,7 +3984,7 @@ begin
 
   if lReqETag <> GetSHA1HashFromString(Data) then
   begin
-    raise EMVCException.Create(HTTP_STATUS.PreconditionFailed, 'mid-air collisions detected, cannot update or delete resource.');
+    raise EMVCException.Create(HTTP_STATUS.PreconditionFailed, 'mid-air collisions detected (invalid "if-match" value), cannot update or delete resource.');
   end;
 end;