diff --git a/cibuild.sh b/cibuild.sh
index e0d226e9..10b77994 100755
--- a/cibuild.sh
+++ b/cibuild.sh
@@ -200,7 +200,7 @@ END
 
     else
         export PGDEBUG=""
-        export CDEBUG="-g0 -O2"
+        export CDEBUG="-g0 -O0"
         cat > ${PG_DEBUG_HEADER} << END
 #ifndef I_PGDEBUG
 #define I_PGDEBUG