diff --git a/audio_a2dp_hw/Android.mk b/audio_a2dp_hw/Android.mk
index db4b7a3..fb509e7 100644
--- a/audio_a2dp_hw/Android.mk
+++ b/audio_a2dp_hw/Android.mk
@@ -7,6 +7,8 @@
 
 LOCAL_C_INCLUDES+= . $(LOCAL_PATH)/../utils/include
 
+LOCAL_CFLAGS += -std=c99
+
 LOCAL_SHARED_LIBRARIES := \
 	libcutils liblog
 
diff --git a/bta/Android.mk b/bta/Android.mk
index bca6c08..65eb952 100644
--- a/bta/Android.mk
+++ b/bta/Android.mk
@@ -8,7 +8,7 @@
 LOCAL_CFLAGS += \
 	-DBOARD_HAVE_BLUETOOTH_BCM
 endif
-LOCAL_CFLAGS += -DBUILDCFG $(bdroid_CFLAGS)
+LOCAL_CFLAGS += -DBUILDCFG $(bdroid_CFLAGS) -std=c99
 
 LOCAL_PRELINK_MODULE:=false
 LOCAL_SRC_FILES:= \
diff --git a/gki/Android.mk b/gki/Android.mk
index ed9f904..4520e45 100644
--- a/gki/Android.mk
+++ b/gki/Android.mk
@@ -11,7 +11,7 @@
                    $(LOCAL_PATH)/../utils/include \
                    $(bdroid_C_INCLUDES) \
 
-LOCAL_CFLAGS += -Werror -Wno-error=unused-parameter $(bdroid_CFLAGS)
+LOCAL_CFLAGS += -Werror -Wno-error=unused-parameter $(bdroid_CFLAGS) -std=c99
 
 ifeq ($(BOARD_HAVE_BLUETOOTH_BCM),true)
 LOCAL_CFLAGS += \
diff --git a/hci/Android.mk b/hci/Android.mk
index 2b1b07e..96f0813 100644
--- a/hci/Android.mk
+++ b/hci/Android.mk
@@ -25,6 +25,8 @@
 
 endif
 
+LOCAL_CFLAGS += -std=c99
+
 LOCAL_C_INCLUDES += \
         $(LOCAL_PATH)/include \
         $(LOCAL_PATH)/../utils/include
diff --git a/main/Android.mk b/main/Android.mk
index 0850bf7..c9c2327 100644
--- a/main/Android.mk
+++ b/main/Android.mk
@@ -100,6 +100,7 @@
 	external/tinyxml2
 
 LOCAL_CFLAGS += -DBUILDCFG $(bdroid_CFLAGS) -Werror -Wno-error=maybe-uninitialized -Wno-error=uninitialized -Wno-error=unused-parameter
+LOCAL_CONLYFLAGS := -std=c99
 
 ifeq ($(TARGET_PRODUCT), full_crespo)
      LOCAL_CFLAGS += -DTARGET_CRESPO
diff --git a/stack/Android.mk b/stack/Android.mk
index 92ce253..12f858e 100644
--- a/stack/Android.mk
+++ b/stack/Android.mk
@@ -32,7 +32,7 @@
                    $(LOCAL_PATH)/../utils/include \
                    $(bdroid_C_INCLUDES) \
 
-LOCAL_CFLAGS += $(bdroid_CFLAGS)
+LOCAL_CFLAGS += $(bdroid_CFLAGS) -std=c99
 
 ifeq ($(BOARD_HAVE_BLUETOOTH_BCM),true)
 LOCAL_CFLAGS += \
diff --git a/test/bluedroidtest/Android.mk b/test/bluedroidtest/Android.mk
index 0c6693a..864bff8 100644
--- a/test/bluedroidtest/Android.mk
+++ b/test/bluedroidtest/Android.mk
@@ -23,6 +23,8 @@
 
 LOCAL_C_INCLUDES :=
 
+LOCAL_CFLAGS += -std=c99
+
 LOCAL_MODULE_TAGS := eng
 
 LOCAL_MODULE:= bdt
diff --git a/utils/Android.mk b/utils/Android.mk
index c74cd2d..4589e5c 100644
--- a/utils/Android.mk
+++ b/utils/Android.mk
@@ -6,7 +6,7 @@
                    $(LOCAL_PATH)/../gki/ulinux \
                    $(bdroid_C_INCLUDES)
 
-LOCAL_CFLAGS += -Werror $(bdroid_CFLAGS)
+LOCAL_CFLAGS += -Werror $(bdroid_CFLAGS) -std=c99
 
 LOCAL_PRELINK_MODULE:=false
 LOCAL_SRC_FILES:= \