diff --git a/native/dicttoolkit/Android.mk b/native/dicttoolkit/Android.mk
index 118682d..4befecf 100644
--- a/native/dicttoolkit/Android.mk
+++ b/native/dicttoolkit/Android.mk
@@ -36,7 +36,7 @@
 
 # To suppress compiler warnings for unused variables/functions used for debug features etc.
 LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 
 include $(LOCAL_PATH)/NativeFileList.mk
 include $(LATIN_IME_CORE_PATH)/NativeFileList.mk
diff --git a/native/dicttoolkit/UnitTests.mk b/native/dicttoolkit/UnitTests.mk
index 96e2873..da1b376 100644
--- a/native/dicttoolkit/UnitTests.mk
+++ b/native/dicttoolkit/UnitTests.mk
@@ -28,10 +28,9 @@
 include $(LOCAL_PATH)/NativeFileList.mk
 include $(LATIN_IME_CORE_PATH)/NativeFileList.mk
 
-# TODO: Remove -std=c++11 once it is set by default on host build.
 LATIN_IME_SRC_DIR := src
 LOCAL_ADDRESS_SANITIZER := true
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_CXX_STL := libc++
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_DICT_TOOLKIT_SRC_DIR) \
@@ -45,9 +44,8 @@
 
 include $(CLEAR_VARS)
 
-# TODO: Remove -std=c++11 once it is set by default on host build.
 LOCAL_ADDRESS_SANITIZER := true
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_CXX_STL := libc++
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_DICT_TOOLKIT_SRC_DIR) \
diff --git a/native/jni/HostUnitTests.mk b/native/jni/HostUnitTests.mk
index e30d50a..6a8bcec 100644
--- a/native/jni/HostUnitTests.mk
+++ b/native/jni/HostUnitTests.mk
@@ -27,10 +27,9 @@
 include $(LOCAL_PATH)/NativeFileList.mk
 
 #################### Host library for unit test
-# TODO: Remove -std=c++11 once it is set by default on host build.
 LATIN_IME_SRC_DIR := src
 LOCAL_ADDRESS_SANITIZER := true
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_CXX_STL := libc++
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
@@ -43,8 +42,7 @@
 include $(CLEAR_VARS)
 LATIN_IME_TEST_SRC_DIR := tests
 LOCAL_ADDRESS_SANITIZER := true
-# TODO: Remove -std=c++11 once it is set by default on host build.
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_CXX_STL := libc++
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
diff --git a/native/jni/TargetUnitTests.mk b/native/jni/TargetUnitTests.mk
index eefd4fc..69a32ed 100644
--- a/native/jni/TargetUnitTests.mk
+++ b/native/jni/TargetUnitTests.mk
@@ -21,7 +21,7 @@
 
 #################### Target library for unit test
 LATIN_IME_SRC_DIR := src
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
 LOCAL_MODULE := liblatinime_target_static_for_unittests
@@ -34,7 +34,7 @@
 #################### Target native tests
 include $(CLEAR_VARS)
 LATIN_IME_TEST_SRC_DIR := tests
-LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CFLAGS += -Wno-unused-parameter -Wno-unused-function
 LOCAL_CLANG := true
 LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
 LOCAL_MODULE := liblatinime_target_unittests
diff --git a/tools/dicttool/NativeLib.mk b/tools/dicttool/NativeLib.mk
index ffb32ed..622a9f1 100644
--- a/tools/dicttool/NativeLib.mk
+++ b/tools/dicttool/NativeLib.mk
@@ -34,9 +34,6 @@
 LOCAL_MULTILIB := 64
 endif #HOST_JDK_IS_64BIT_VERSION
 
-# For C++11
-LOCAL_CFLAGS += -std=c++11
-
 LATINIME_NATIVE_JNI_DIR := $(LATINIME_DIR_RELATIVE_TO_DICTTOOL)/native/jni
 LATINIME_NATIVE_SRC_DIR := $(LATINIME_DIR_RELATIVE_TO_DICTTOOL)/native/jni/src
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/$(LATINIME_NATIVE_SRC_DIR)