diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 5bd34072..1e8d3500 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -3579,7 +3579,7 @@ __PACKAGE__->register_method({
 	    PVE::Storage::activate_volumes($storecfg, [$volid]);
 	    my $size = PVE::Storage::volume_size_info($storecfg, $volid, 5);
 
-	    die "Size of volume $volid couldn't be determined\n" if (!defined($size));
+	    die "Could not determine current size of volume '$volid'\n" if !defined($size);
 
 	    die "internal error" if $sizestr !~ m/^(\+)?(\d+(\.\d+)?)([KMGT])?$/;
 	    my ($ext, $newsize, $unit) = ($1, $2, $4);