diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0172dbc..2655e34 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -149,10 +149,6 @@ jobs:
 
       - name: Run tests
         run: |
-          if [[ "${{ matrix.target.os }}" == "windows" ]]; then
-            # https://github.com/status-im/nimbus-eth2/issues/3121
-            export NIMFLAGS="-d:nimRawSetjmp"
-          fi
           nim --version
           nimble --version
           env TEST_LANG=c nimble test
diff --git a/config.nims b/config.nims
new file mode 100644
index 0000000..c5cadd9
--- /dev/null
+++ b/config.nims
@@ -0,0 +1,4 @@
+if defined(windows):
+  # Avoid some rare stack corruption while using exceptions with a SEH-enabled
+  # toolchain: https://github.com/status-im/nimbus-eth2/issues/3121
+  switch("define", "nimRawSetjmp")
diff --git a/tests/config.nims b/tests/config.nims
new file mode 100644
index 0000000..c5cadd9
--- /dev/null
+++ b/tests/config.nims
@@ -0,0 +1,4 @@
+if defined(windows):
+  # Avoid some rare stack corruption while using exceptions with a SEH-enabled
+  # toolchain: https://github.com/status-im/nimbus-eth2/issues/3121
+  switch("define", "nimRawSetjmp")