diff --git a/lib/spack/spack/solver/asp.py b/lib/spack/spack/solver/asp.py
index 289f9de8a9f..8214f531d9e 100644
--- a/lib/spack/spack/solver/asp.py
+++ b/lib/spack/spack/solver/asp.py
@@ -1190,7 +1190,7 @@ def solve(self, setup, specs, reuse=None, output=None, control=None, allow_depre
                 problem_repr += "\n" + f.read()
 
         result = None
-        conc_cache_enabled = spack.config.get("config:concretization_cache:enable", True)
+        conc_cache_enabled = spack.config.get("config:concretization_cache:enable", False)
         if conc_cache_enabled:
             result, concretization_stats = CONC_CACHE.fetch(problem_repr)