diff --git a/nim.cfg b/nim.cfg
new file mode 100644
index 000000000..678e7e818
--- /dev/null
+++ b/nim.cfg
@@ -0,0 +1,11 @@
+# TODO - https://github.com/status-im/nimbus/issues/9
+# Workaround for Rlp + TT-math:
+# use GCC on MacOS
+
+@if macosx:
+  cc:"gcc"
+  gcc.exe:"/usr/local/bin/gcc-7"
+  gcc.linkerexe:"/usr/local/bin/gcc-7"
+  gcc.cpp.exe:"/usr/local/bin/g++-7"
+  gcc.cpp.linkerexe:"/usr/local/bin/g++-7"
+@end