diff --git a/embedding/browser/build/Makefile.in b/embedding/browser/build/Makefile.in
index a0985a5ebe4f..f156e5dda421 100644
--- a/embedding/browser/build/Makefile.in
+++ b/embedding/browser/build/Makefile.in
@@ -14,6 +14,7 @@ IS_COMPONENT	= 1
 MODULE_NAME	= Browser_Embedding_Module
 EXPORT_LIBRARY	= 1
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 
 SHARED_LIBRARY_LIBS= \
diff --git a/embedding/browser/webBrowser/Makefile.in b/embedding/browser/webBrowser/Makefile.in
index 937e57212b86..1c03b264badb 100644
--- a/embedding/browser/webBrowser/Makefile.in
+++ b/embedding/browser/webBrowser/Makefile.in
@@ -11,7 +11,7 @@ VPATH		= @srcdir@
 include $(DEPTH)/config/autoconf.mk
 
 LIBXUL_LIBRARY	= 1
-
+FAIL_ON_WARNINGS = 1
 
 
 LOCAL_INCLUDES	= \
diff --git a/embedding/components/appstartup/src/Makefile.in b/embedding/components/appstartup/src/Makefile.in
index dd8bf779321e..97b298bfadc4 100644
--- a/embedding/components/appstartup/src/Makefile.in
+++ b/embedding/components/appstartup/src/Makefile.in
@@ -11,6 +11,7 @@ VPATH		= @srcdir@
 include $(DEPTH)/config/autoconf.mk
 
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.
diff --git a/embedding/components/build/Makefile.in b/embedding/components/build/Makefile.in
index aefb05e74db4..1d39b9bc3572 100644
--- a/embedding/components/build/Makefile.in
+++ b/embedding/components/build/Makefile.in
@@ -13,6 +13,7 @@ EXPORT_LIBRARY = 1
 IS_COMPONENT	= 1
 MODULE_NAME	= embedcomponents
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 SHARED_LIBRARY_LIBS = \
 	../windowwatcher/src/$(LIB_PREFIX)windowwatcher_s.$(LIB_SUFFIX) \
diff --git a/embedding/components/printingui/src/mac/Makefile.in b/embedding/components/printingui/src/mac/Makefile.in
index 0f927a9a17f9..a67c46bce1bb 100644
--- a/embedding/components/printingui/src/mac/Makefile.in
+++ b/embedding/components/printingui/src/mac/Makefile.in
@@ -12,7 +12,7 @@ include $(DEPTH)/config/autoconf.mk
 
 EXPORT_LIBRARY	= ..
 LIBXUL_LIBRARY	= 1
-
+FAIL_ON_WARNINGS = 1
 
 
 DISABLED_CMMSRCS = nsPrintingPromptServiceX.mm
diff --git a/embedding/components/printingui/src/unixshared/Makefile.in b/embedding/components/printingui/src/unixshared/Makefile.in
index e710e153df6a..f698cb578170 100644
--- a/embedding/components/printingui/src/unixshared/Makefile.in
+++ b/embedding/components/printingui/src/unixshared/Makefile.in
@@ -12,6 +12,7 @@ include $(DEPTH)/config/autoconf.mk
 
 EXPORT_LIBRARY	= ..
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.
diff --git a/embedding/components/printingui/src/win/Makefile.in b/embedding/components/printingui/src/win/Makefile.in
index e710e153df6a..f698cb578170 100644
--- a/embedding/components/printingui/src/win/Makefile.in
+++ b/embedding/components/printingui/src/win/Makefile.in
@@ -12,6 +12,7 @@ include $(DEPTH)/config/autoconf.mk
 
 EXPORT_LIBRARY	= ..
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.
diff --git a/embedding/components/webbrowserpersist/src/Makefile.in b/embedding/components/webbrowserpersist/src/Makefile.in
index dd8bf779321e..97b298bfadc4 100644
--- a/embedding/components/webbrowserpersist/src/Makefile.in
+++ b/embedding/components/webbrowserpersist/src/Makefile.in
@@ -11,6 +11,7 @@ VPATH		= @srcdir@
 include $(DEPTH)/config/autoconf.mk
 
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.
diff --git a/embedding/components/windowwatcher/src/Makefile.in b/embedding/components/windowwatcher/src/Makefile.in
index 50cbecff5c49..26be09244f4d 100644
--- a/embedding/components/windowwatcher/src/Makefile.in
+++ b/embedding/components/windowwatcher/src/Makefile.in
@@ -11,6 +11,7 @@ VPATH		= @srcdir@
 include $(DEPTH)/config/autoconf.mk
 
 LIBXUL_LIBRARY	= 1
+FAIL_ON_WARNINGS = 1
 
 # we don't want the shared lib, but we want to force the creation of a
 # static lib.