diff --git a/pytensor/link/c/basic.py b/pytensor/link/c/basic.py
index ab61e4e4bd..cf47b3aa6d 100644
--- a/pytensor/link/c/basic.py
+++ b/pytensor/link/c/basic.py
@@ -651,7 +651,8 @@ def fetch_variables(self):
             ):
                 self.consts.append(variable)
                 self.orphans.remove(variable)
-
+        if self.consts:
+            raise ValueError("There are consts after all")
         self.temps = list(
             set(self.variables)
             .difference(self.inputs)