diff --git a/make/defs.mk b/make/defs.mk
index 010885c8..f655cc20 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -9,6 +9,7 @@ MAKEFLAGS                   += -r
 
 empty                       :=
 space                       := $(empty) $(empty)
+comma                       := ,
 
 include $(MODDIR)/make/projects.mk
 
diff --git a/make/targets-tools.mk b/make/targets-tools.mk
index f9c620af..e2ae5d40 100644
--- a/make/targets-tools.mk
+++ b/make/targets-tools.mk
@@ -70,9 +70,6 @@ CLANG_TIDY_EXTRA_ARGS       += -cppcoreguidelines-pro-bounds-pointer-arithmetic
 CLANG_TIDY_EXTRA_ARGS       += -cppcoreguidelines-pro-bounds-constant-array-index
 
 CLANG_TIDY_FILTER            = $(SED) 's%\[\([a-z-]\+\)\]$$%[https://clang.llvm.org/extra/clang-tidy/checks/\1.html]%'
-comma                       := ,
-empty                       :=
-space                       := $(empty) $(empty)
 CLANG_TIDY_CHECKS           ?= -$(subst  $(space),,*,clang-analyzer-*,-clang-analyzer-cplusplus*,modernize-*,portability-*,cppcoreguidelines-*$(addprefix $(comma),$(CLANG_TIDY_EXTRA_ARGS)))
 CLANG_TIDY                  ?= clang-tidy -checks=$(CLANG_TIDY_CHECKS)