diff --git a/Makefile b/Makefile
index 9d0f09ce2..1206da36f 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ ENV_SCRIPT := "$(CURDIR)/env.sh"
 # duplicated in "env.sh" to prepend NIM_DIR/bin to PATH
 NIM_DIR := vendor/Nim
 # extra parameters for the Nim compiler
-NIM_PARAMS :=
+NIM_PARAMS := $(EXTRA_NIM_PARAMS)
 # verbosity level
 V := 1
 NIM_PARAMS := $(NIM_PARAMS) --verbosity:$(V)
diff --git a/README.md b/README.md
index cdb0a788c..292f333ff 100644
--- a/README.md
+++ b/README.md
@@ -115,6 +115,12 @@ make LOG_LEVEL=DEBUG nimbus # this is the default
 make LOG_LEVEL=TRACE nimbus # log everything
 ```
 
+- pass arbitrary parameters to the Nim compiler:
+
+```bash
+make EXTRA_NIM_PARAMS="-d:release"
+```
+
 - if you want to use SSH keys with GitHub:
 
 ```bash