diff --git a/browser/app/Makefile.in b/browser/app/Makefile.in
index dcbe324a0983..491731f7ff28 100644
--- a/browser/app/Makefile.in
+++ b/browser/app/Makefile.in
@@ -32,22 +32,22 @@ CXXFLAGS += -mno-sse -mno-sse2 -mfpmath=387
 CXX += -march=pentiumpro
 endif
 
-ifeq ($(OS_ARCH),WINNT)
-# Rebuild firefox.exe if the manifest changes - it's included by splash.rc.
-# (this dependency should really be just for firefox.exe, not other targets)
-# Note the manifest file exists in the tree, so we use the explicit filename
-# here.
-ifdef HAVE_64BIT_BUILD
-EXTRA_DEPS += firefox.exe.64.manifest
-else
-EXTRA_DEPS += firefox.exe.32.manifest
-endif
-endif
-
 PROGRAMS_DEST = $(DIST)/bin
 
 include $(topsrcdir)/config/rules.mk
 
+ifeq ($(OS_ARCH),WINNT)
+# Rebuild a .res file if the manifest changes - it's included by splash.rc.
+# (this dependency should really be just for the .res file, not other targets)
+# Note the manifest file exists in the tree, so we use the explicit filename
+# here.
+ifdef HAVE_64BIT_BUILD
+$(RESFILE): firefox.exe.64.manifest
+else
+$(RESFILE): firefox.exe.32.manifest
+endif
+endif
+
 ifneq (,$(filter-out WINNT,$(OS_ARCH)))
 
 ifdef COMPILE_ENVIRONMENT
diff --git a/ipc/app/Makefile.in b/ipc/app/Makefile.in
index 7b8cd7af22ed..9714ea1fe646 100644
--- a/ipc/app/Makefile.in
+++ b/ipc/app/Makefile.in
@@ -26,9 +26,9 @@ ifeq ($(OS_ARCH),WINNT) #{
 # Note the manifest file exists in the tree, so we use the explicit filename
 # here.
 ifdef HAVE_64BIT_BUILD
-EXTRA_DEPS += plugin-container.exe.64.manifest
+$(RESFILE): plugin-container.exe.64.manifest
 else
-EXTRA_DEPS += plugin-container.exe.32.manifest
+$(RESFILE): plugin-container.exe.32.manifest
 endif
 endif #}