diff --git a/subdir.mak b/subdir.mak
index d89573904e..eb9a70f97f 100644
--- a/subdir.mak
+++ b/subdir.mak
@@ -5,7 +5,7 @@ include $(SUBDIR)../common.mak
 LIBVERSION := $(lib$(NAME)_VERSION)
 LIBMAJOR   := $(lib$(NAME)_VERSION_MAJOR)
 
-ifeq ($(CONFIG_STATIC),yes)
+ifdef CONFIG_STATIC
 all: $(SUBDIR)$(LIBNAME)
 
 install-libs: install-lib$(NAME)-static