diff --git a/scst/Makefile b/scst/Makefile
index e6443f0c4..53e1892b9 100644
--- a/scst/Makefile
+++ b/scst/Makefile
@@ -24,12 +24,14 @@ SCST_DIR=src
 
 # Set variable $(2) to value $(3) in file $(1) if $(2)=$(3) does not yet occur
 # in file $(1).
-set_var = $(shell if grep -q '^$(2)=' '$(1)' 2>/dev/null; then	\
-		    grep -q '^$(2)=$(3)$$' '$(1)' ||		\
-		      sed -i 's/^$(2)=.*/$(2)=$(3)/' '$(1)';	\
-		  else						\
-		    echo '$(2)=$(3)' >> '$(1)';			\
-		  fi)
+define set_var
+if grep -q '^$(2)=' '$(1)' 2>/dev/null; then			\
+	grep -q '^$(2)=$(3)$$' '$(1)' ||				\
+		sed -i 's/^$(2)=.*/$(2)=$(3)/' '$(1)';		\
+else								\
+	echo '$(2)=$(3)' >> '$(1)';				\
+fi
+endef
 
 all: include/build_mode.h
 	cd $(SCST_DIR) && $(MAKE) $@
@@ -48,23 +50,20 @@ extraclean:
 	cd $(SCST_DIR) && $(MAKE) $@
 
 2debug:
-	$(call set_var,build_mode,BUILD_MODE,)
-	@true
+	@$(call set_var,build_mode,BUILD_MODE,)
 
 2release:
-	$(call set_var,build_mode,BUILD_MODE,RELEASE)
-	@true
+	@$(call set_var,build_mode,BUILD_MODE,RELEASE)
 
 2perf:
-	$(call set_var,build_mode,BUILD_MODE,PERF)
-	@true
+	@$(call set_var,build_mode,BUILD_MODE,PERF)
 
 release-archive:
 	../scripts/generate-release-archive scst \
 	  "$$(sed -n 's/^#define[[:blank:]]SCST_VERSION_NAME[[:blank:]]*\"\([^\"]*\)\".*/\1/p' include/scst_const.h)"
 
 build_mode:
-	$(call set_var,build_mode,BUILD_MODE,)
+	@$(call set_var,build_mode,BUILD_MODE,)
 
 include/build_mode.h: build_mode
 	@rm -f $@.tmp;							\