diff --git a/package.yaml b/package.yaml
index d6dbf4805..32bf3922d 100644
--- a/package.yaml
+++ b/package.yaml
@@ -256,21 +256,25 @@ ghc-options:
   - -fno-max-relevant-binds
   - -j
   - -freduction-depth=0
+  - +RTS -K0 -RTS
 when:
   - condition: flag(pedantic)
     ghc-options:
       - -Werror
       - -fwarn-tabs
+      - -O0
   - condition: flag(dev)
     then:
       ghc-options:
         - -O0
         - -ddump-splices
         - -ddump-to-file
+        - -Wderiving-typeable
       cpp-options: -DDEVELOPMENT
     else:
       ghc-options:
-        - -O
+        - -O0        
+        # -fllvm
 data-files:
   - testdata/**
 library: