diff --git a/Makefile.include b/Makefile.include
index 9e8e8f78f8..f9ed21b6a1 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -141,6 +141,14 @@ ifeq ($(DEVELHELP),1)
   CFLAGS += -DDEVELHELP
 endif
 
+# Override LOG_LEVEL if variable is set and if CFLAGS doesn't already contain
+# a LOG_LEVEL config
+ifdef LOG_LEVEL
+  ifneq (,$(filter -DLOG_LEVEL=%,$(CFLAGS)))
+    CFLAGS += -DLOG_LEVEL=$(LOG_LEVEL)
+  endif
+endif
+
 # Fail on warnings. Can be overridden by `make WERROR=0`.
 WERROR ?= 1
 export WERROR
diff --git a/makefiles/vars.inc.mk b/makefiles/vars.inc.mk
index f2c5ac9ed0..b46d5f70b5 100644
--- a/makefiles/vars.inc.mk
+++ b/makefiles/vars.inc.mk
@@ -95,3 +95,5 @@ export UNZIP_HERE            # Use `cd $(SOME_FOLDER) && $(UNZIP_HERE) $(SOME_FI
 
 export LAZYSPONGE            # Command saving stdin to a file only on content update.
 export LAZYSPONGE_FLAGS      # Parameters supplied to LAZYSPONGE.
+
+# LOG_LEVEL                  # Logging level as integer (NONE: 0, ERROR: 1, WARNING: 2, INFO: 3, DEBUG: 4, default: 3)