diff --git a/accessible/public/ia2/Makefile.in b/accessible/public/ia2/Makefile.in
index 6f4dce27bc9..1b81227eb9a 100644
--- a/accessible/public/ia2/Makefile.in
+++ b/accessible/public/ia2/Makefile.in
@@ -99,8 +99,6 @@ MIDL_GENERATED_FILES = \
   $(MIDL_ENUMS:%.idl=%.h) \
   $(NULL)
 
-EMBED_MANIFEST_AT = 2
-
 include $(topsrcdir)/config/rules.mk
 
 OS_LIBS = \
diff --git a/accessible/public/msaa/Makefile.in b/accessible/public/msaa/Makefile.in
index c37544eaa00..c473e8069d4 100755
--- a/accessible/public/msaa/Makefile.in
+++ b/accessible/public/msaa/Makefile.in
@@ -119,7 +119,5 @@ export:: done_gen
 register::
 	regsvr32 -s $(DIST)/bin/$(SHARED_LIBRARY)
 
-EMBED_MANIFEST_AT = 2
-
 include $(topsrcdir)/config/rules.mk
 
diff --git a/config/rules.mk b/config/rules.mk
index 3e9251d6fb4..2523b1ef892 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -1129,12 +1129,10 @@ endif # NO_LD_ARCHIVE_FLAGS
 	$(MKSHLIB) $(SHLIB_LDSTARTFILE) $(OBJS) $(LOBJS) $(SUB_SHLOBJS) $(RESFILE) $(LDFLAGS) $(EXTRA_DSO_LDOPTS) $(OS_LIBS) $(EXTRA_LIBS) $(DEF_FILE) $(SHLIB_LDENDFILE)
 ifeq (_WINNT,$(GNU_CC)_$(OS_ARCH))
 ifdef MSMANIFEST_TOOL
-ifdef EMBED_MANIFEST_AT
 	@if test -f $@.manifest; then \
-		mt.exe -NOLOGO -MANIFEST $@.manifest -OUTPUTRESOURCE:$@\;$(EMBED_MANIFEST_AT); \
+		mt.exe -NOLOGO -MANIFEST $@.manifest -OUTPUTRESOURCE:$@\;2; \
 		rm -f $@.manifest; \
 	fi
-endif   # embed manifest
 endif	# MSVC with manifest tool
 endif	# WINNT && !GCC
 	@rm -f foodummyfilefoo $(SUB_SHLOBJS) $(DELETE_AFTER_LINK)
diff --git a/embedding/browser/activex/src/control/Makefile.in b/embedding/browser/activex/src/control/Makefile.in
index 9cb9a88f227..68157ebef25 100644
--- a/embedding/browser/activex/src/control/Makefile.in
+++ b/embedding/browser/activex/src/control/Makefile.in
@@ -114,8 +114,6 @@ GARBAGE	+= $(DEFFILE) $(MIDL_GENERATED_FILES) done_gen
 
 ENABLE_CXX_EXCEPTIONS = 1
 
-EMBED_MANIFEST_AT = 2
-
 include $(topsrcdir)/config/rules.mk
 
 CXXFLAGS += -D "WIN32" -U "ClientWallet"
diff --git a/embedding/browser/activex/src/control_kicker/Makefile.in b/embedding/browser/activex/src/control_kicker/Makefile.in
index 7680d5f14fe..e0beb1f391b 100644
--- a/embedding/browser/activex/src/control_kicker/Makefile.in
+++ b/embedding/browser/activex/src/control_kicker/Makefile.in
@@ -64,8 +64,6 @@ OS_LIBS	+= \
 	
 ENABLE_CXX_EXCEPTIONS = 1
 
-EMBED_MANIFEST_AT = 2
-
 include $(topsrcdir)/config/rules.mk
 
 CXXFLAGS += -D "WIN32" -GF -MT -O1
diff --git a/xpinstall/stub/Makefile.in b/xpinstall/stub/Makefile.in
index 1aae5f17e06..cba21bfa9c8 100644
--- a/xpinstall/stub/Makefile.in
+++ b/xpinstall/stub/Makefile.in
@@ -67,5 +67,4 @@ EXTRA_DSO_LDOPTS= \
 		$(MOZ_COMPONENT_LIBS) \
 		$(NULL)
 
-EMBED_MANIFEST_AT = 17
 include $(topsrcdir)/config/rules.mk