diff --git a/stubdom/Makefile b/stubdom/Makefile
index c41de27486..6bea68b1d3 100644
--- a/stubdom/Makefile
+++ b/stubdom/Makefile
@@ -210,6 +210,7 @@ tpm_emulator-$(XEN_TARGET_ARCH): tpm_emulator-$(TPMEMU_VERSION).tar.gz
 	patch -d $@ -p1 < vtpm-locality.patch
 	patch -d $@ -p1 < vtpm-parent-sign-ek.patch
 	patch -d $@ -p1 < vtpm-deepquote.patch
+	patch -d $@ -p1 < vtpm-cmake-Wextra.patch
 	mkdir $@/build
 	cd $@/build; CC=${CC} $(CMAKE) .. -DCMAKE_C_FLAGS:STRING="-std=c99 -DTPM_NO_EXTERN $(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -Wno-declaration-after-statement"
 	touch $@
diff --git a/stubdom/vtpm-cmake-Wextra.patch b/stubdom/vtpm-cmake-Wextra.patch
new file mode 100644
index 0000000000..a603654667
--- /dev/null
+++ b/stubdom/vtpm-cmake-Wextra.patch
@@ -0,0 +1,21 @@
+---
+ CMakeLists.txt |    3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+Index: tpm_emulator-x86_64/CMakeLists.txt
+===================================================================
+--- tpm_emulator-x86_64.orig/CMakeLists.txt
++++ tpm_emulator-x86_64/CMakeLists.txt
+@@ -40,10 +40,11 @@ set(TPM_STORAGE_NAME "/var/lib/tpm/tpm_e
+ set(TPM_DEVICE_NAME "/dev/tpm")
+ endif()
+ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/config.h.in ${CMAKE_CURRENT_BINARY_DIR}/config.h)
+-add_definitions(-Wall -Werror -Wno-unused-parameter -Wpointer-arith -Wcast-align -Wwrite-strings)
++add_definitions(-Wall -Werror)
+ if("${CMAKE_SYSTEM}" MATCHES "Linux")
+     add_definitions(-Wextra)
+ endif()
++add_definitions(-Wno-unused-parameter -Wpointer-arith -Wcast-align -Wwrite-strings)
+ if(USE_OPENSSL)
+     add_definitions(-DUSE_OPENSSL)
+ endif()