diff --git a/advancecomp.spec b/advancecomp.spec
index 3cb9413..cd174f9 100644
--- a/advancecomp.spec
+++ b/advancecomp.spec
@@ -122,6 +122,11 @@ export LDFLAGS="-lzopfli ${LDFLAGS-}"
 %make_install
 
 
+# We don’t run upstream tests (%%make_build check) because they are too
+# brittle, expecting recompressed outputs to be identical. Across platforms,
+# compilers, and unbundled library versions, this doesn’t hold up.
+
+
 %files
 %license COPYING
 %doc AUTHORS