diff --git a/toolkit/mozapps/installer/packager.mk b/toolkit/mozapps/installer/packager.mk
index 1851a606cf4d..c3c51019b75e 100644
--- a/toolkit/mozapps/installer/packager.mk
+++ b/toolkit/mozapps/installer/packager.mk
@@ -103,7 +103,7 @@ JSSHELL_BINS += \
 endif # MOZ_FOLD_LIBS
 endif # MOZ_NATIVE_NSPR
 ifdef MOZ_SHARED_ICU
-ifdef XP_WIN
+ifeq ($(OS_TARGET), WINNT)
 ifdef MOZ_DEBUG
 JSSHELL_BINS += \
   $(DIST)/bin/icudtd$(MOZ_ICU_VERSION).dll \
@@ -118,22 +118,20 @@ JSSHELL_BINS += \
   $(NULL)
 endif # MOZ_DEBUG
 else
-ifdef XP_MACOSX
+ifeq ($(OS_TARGET), Darwin)
 JSSHELL_BINS += \
   $(DIST)/bin/libicudata.$(MOZ_ICU_VERSION).dylib \
   $(DIST)/bin/libicui18n.$(MOZ_ICU_VERSION).dylib \
   $(DIST)/bin/libicuuc.$(MOZ_ICU_VERSION).dylib \
   $(NULL)
 else
-ifdef XP_UNIX
 JSSHELL_BINS += \
   $(DIST)/bin/libicudata.so.$(MOZ_ICU_VERSION) \
   $(DIST)/bin/libicui18n.so.$(MOZ_ICU_VERSION) \
   $(DIST)/bin/libicuuc.so.$(MOZ_ICU_VERSION) \
   $(NULL)
-endif # XP_UNIX
-endif # XP_MACOSX
-endif # XP_WIN
+endif # Darwin
+endif # WINNT
 endif # MOZ_STATIC_JS
 MAKE_JSSHELL  = $(ZIP) -9j $(PKG_JSSHELL) $(JSSHELL_BINS)
 endif # LIBXUL_SDK