diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5d5beac92..334360dbd 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -142,7 +142,7 @@ jobs:
 
       - name: Build binaries (with trace logging enabled)
         run: |
-          ${make_cmd} -j ${ncpu} V=1 NIM_COMMIT=${{ matrix.branch }} LOG_LEVEL=TRACE
+          ${make_cmd} -j ${ncpu} V=1 NIM_COMMIT=${{ matrix.branch }} LOG_LEVEL=TRACE NIMFLAGS="-u:release --opt:none"
           # The Windows image runs out of disk space, so make some room
           rm -rf build nimcache
 
diff --git a/Makefile b/Makefile
index c95edc587..325cf1cd9 100644
--- a/Makefile
+++ b/Makefile
@@ -144,7 +144,7 @@ DEPOSITS_DELAY := 0
 #- "--define:release" cannot be added to "config.nims"
 #- disable Nim's default parallelisation because it starts too many processes for too little gain
 #- https://github.com/status-im/nim-libp2p#use-identify-metrics
-NIM_PARAMS += -d:release --parallelBuild:1 -d:libp2p_agents_metrics -d:KnownLibP2PAgents=nimbus,lighthouse,lodestar,prysm,teku
+NIM_PARAMS := -d:release --parallelBuild:1 -d:libp2p_agents_metrics -d:KnownLibP2PAgents=nimbus,lighthouse,lodestar,prysm,teku $(NIM_PARAMS)
 
 ifeq ($(USE_LIBBACKTRACE), 0)
 NIM_PARAMS += -d:disable_libbacktrace