diff --git a/metropolis/node/core/curator/filters.go b/metropolis/node/core/curator/filters.go
index 1e43314..4a100bb 100644
--- a/metropolis/node/core/curator/filters.go
+++ b/metropolis/node/core/curator/filters.go
@@ -43,7 +43,7 @@
 	env, err := cel.NewEnv(opts...)
 	if err != nil {
 		rpc.Trace(ctx).Printf("Couldn't create a CEL environment: %v", err)
-		return nil, status.Errorf(codes.Unavailable, "couldn't process the filter expression")
+		return nil, status.Errorf(codes.Unavailable, "couldn't process the filter expression: %v", err)
 	}
 
 	// Parse and type-check the expression.
@@ -73,7 +73,7 @@
 	out, _, err := fprg.Eval(varmap)
 	if err != nil {
 		rpc.Trace(ctx).Printf("Couldn't evaluate a CEL program: %v", err)
-		return false, status.Errorf(codes.Unavailable, "couldn't process the filter expression")
+		return false, status.Errorf(codes.Unavailable, "couldn't evaluate the filter expression: %v", err)
 	}
 
 	res := out.ConvertToType(celtypes.BoolType)