diff --git a/sumpy/symbolic.py b/sumpy/symbolic.py
index 49fa405929ed713579b27e2b52d6af2493da482b..2cfc90ba75baf4852e52865a6312cd4087b635c0 100644
--- a/sumpy/symbolic.py
+++ b/sumpy/symbolic.py
@@ -63,7 +63,7 @@ def _find_symbolic_backend():
         if backend == "symengine" and not symengine_found:
             raise RuntimeError("could not find SymEngine: %s" % symengine_error)
 
-        USE_SYMENGINE = True
+        USE_SYMENGINE = (backend == "symengine")
     else:
         USE_SYMENGINE = symengine_found