diff --git a/core/binary.mk b/core/binary.mk
index bda9f2e..df176f1 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -116,7 +116,7 @@
 # MinGW spits out warnings about -fPIC even for -fpie?!) being ignored because
 # all code is position independent, and then those warnings get promoted to
 # errors.
-ifeq ($(strip $(USE_MINGW)),)
+ifndef USE_MINGW
 ifeq ($(LOCAL_MODULE_CLASS),EXECUTABLES)
 my_cflags += -fpie
 else
diff --git a/core/combo/HOST_windows-x86.mk b/core/combo/HOST_windows-x86.mk
index 4d871d8..766c14a 100644
--- a/core/combo/HOST_windows-x86.mk
+++ b/core/combo/HOST_windows-x86.mk
@@ -24,7 +24,7 @@
 
 # Settings to use MinGW has a cross-compiler under Linux
 ifneq ($(findstring Linux,$(UNAME)),)
-ifneq ($(strip $(USE_MINGW)),)
+ifdef USE_MINGW
 HOST_ACP_UNAVAILABLE := true
 TOOLS_EXE_SUFFIX :=
 $(combo_2nd_arch_prefix)HOST_GLOBAL_CFLAGS += -DUSE_MINGW
diff --git a/core/combo/HOST_windows-x86_64.mk b/core/combo/HOST_windows-x86_64.mk
index c77d82c..bd392ea 100644
--- a/core/combo/HOST_windows-x86_64.mk
+++ b/core/combo/HOST_windows-x86_64.mk
@@ -24,7 +24,7 @@
 
 # Settings to use MinGW has a cross-compiler under Linux
 ifneq ($(findstring Linux,$(UNAME)),)
-ifneq ($(strip $(USE_MINGW)),)
+ifdef USE_MINGW
 HOST_ACP_UNAVAILABLE := true
 TOOLS_EXE_SUFFIX :=
 HOST_GLOBAL_CFLAGS += -DUSE_MINGW
diff --git a/core/envsetup.mk b/core/envsetup.mk
index d0b5846..87371b9 100644
--- a/core/envsetup.mk
+++ b/core/envsetup.mk
@@ -58,7 +58,7 @@
 # Under Linux, if USE_MINGW is set, we change HOST_OS to Windows to build the
 # Windows SDK. Only a subset of tools and SDK will manage to build properly.
 ifeq ($(HOST_OS),linux)
-ifneq ($(USE_MINGW),)
+ifdef USE_MINGW
   HOST_OS := windows
 endif
 endif