diff --git a/libbacktrace/Android.mk b/libbacktrace/Android.mk
index 632b1b6..356ab8b 100644
--- a/libbacktrace/Android.mk
+++ b/libbacktrace/Android.mk
@@ -25,7 +25,9 @@
 
 libbacktrace_common_cppflags := \
 	-std=gnu++11 \
-	-I external/libunwind/include/tdep \
+
+libbacktrace_common_c_includes := \
+	external/libunwind/include/tdep \
 
 # The latest clang (r230699) does not allow SP/PC to be declared in inline asm lists.
 libbacktrace_common_clang_cflags += \
diff --git a/libnativebridge/Android.mk b/libnativebridge/Android.mk
index d20d44c..b88621e 100644
--- a/libnativebridge/Android.mk
+++ b/libnativebridge/Android.mk
@@ -10,12 +10,11 @@
 LOCAL_MODULE:= libnativebridge
 
 LOCAL_SRC_FILES:= $(NATIVE_BRIDGE_COMMON_SRC_FILES)
-LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_SHARED_LIBRARIES := liblog libdl
 LOCAL_CLANG := true
 LOCAL_CPP_EXTENSION := .cc
 LOCAL_CFLAGS += -Werror -Wall
 LOCAL_CPPFLAGS := -std=gnu++11 -fvisibility=protected
-LOCAL_LDFLAGS := -ldl
 LOCAL_MULTILIB := both
 
 include $(BUILD_SHARED_LIBRARY)
diff --git a/libnativebridge/tests/Android.nativebridge-dummy.mk b/libnativebridge/tests/Android.nativebridge-dummy.mk
index 2efc176..551765a 100644
--- a/libnativebridge/tests/Android.nativebridge-dummy.mk
+++ b/libnativebridge/tests/Android.nativebridge-dummy.mk
@@ -13,7 +13,7 @@
 LOCAL_CLANG := true
 LOCAL_CFLAGS += -Werror -Wall
 LOCAL_CPPFLAGS := -std=gnu++11 -fvisibility=protected
-LOCAL_LDFLAGS := -ldl
+LOCAL_SHARED_LIBRARIES := libdl
 LOCAL_MULTILIB := both
 
 include $(BUILD_SHARED_LIBRARY)
@@ -49,7 +49,7 @@
 LOCAL_CLANG := true
 LOCAL_CFLAGS += -Werror -Wall
 LOCAL_CPPFLAGS := -std=gnu++11 -fvisibility=protected
-LOCAL_LDFLAGS := -ldl
+LOCAL_SHARED_LIBRARIES := libdl
 LOCAL_MULTILIB := both
 
 include $(BUILD_SHARED_LIBRARY)
diff --git a/libnativeloader/Android.mk b/libnativeloader/Android.mk
index 632c6c8..c81c671 100644
--- a/libnativeloader/Android.mk
+++ b/libnativeloader/Android.mk
@@ -12,12 +12,11 @@
 LOCAL_MODULE:= libnativeloader
 
 LOCAL_SRC_FILES:= $(native_loader_common_src_files)
-LOCAL_SHARED_LIBRARIES := libnativehelper liblog libcutils
+LOCAL_SHARED_LIBRARIES := libnativehelper liblog libcutils libdl
 LOCAL_STATIC_LIBRARIES := libbase
 LOCAL_CLANG := true
 LOCAL_CFLAGS := $(native_loader_common_cflags)
 LOCAL_CPPFLAGS := -std=gnu++14 -fvisibility=hidden
-LOCAL_LDFLAGS := -ldl
 LOCAL_MULTILIB := both
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
diff --git a/toolbox/Android.mk b/toolbox/Android.mk
index d151ad6..ba04364 100644
--- a/toolbox/Android.mk
+++ b/toolbox/Android.mk
@@ -3,7 +3,6 @@
 
 common_cflags := \
     -Werror -Wno-unused-parameter -Wno-unused-const-variable \
-    -I$(LOCAL_PATH)/upstream-netbsd/include/ \
     -include bsd-compatibility.h \
 
 
@@ -21,6 +20,7 @@
     upstream-netbsd/lib/libc/string/swab.c \
     upstream-netbsd/lib/libutil/raise_default_signal.c
 LOCAL_CFLAGS += $(common_cflags) -Dmain=dd_main -DNO_CONV
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/upstream-netbsd/include/
 LOCAL_MODULE := libtoolbox_dd
 include $(BUILD_STATIC_LIBRARY)
 
@@ -49,6 +49,7 @@
     $(patsubst %,%.c,$(OUR_TOOLS)) \
 
 LOCAL_CFLAGS += $(common_cflags)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/upstream-netbsd/include/
 LOCAL_CONLYFLAGS += -std=gnu99
 
 LOCAL_SHARED_LIBRARIES := \
@@ -95,6 +96,7 @@
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := r.c
 LOCAL_CFLAGS += $(common_cflags)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/upstream-netbsd/include/
 LOCAL_MODULE := r
 LOCAL_MODULE_TAGS := debug
 include $(BUILD_EXECUTABLE)
@@ -109,6 +111,7 @@
     upstream-netbsd/usr.bin/grep/queue.c \
     upstream-netbsd/usr.bin/grep/util.c
 LOCAL_CFLAGS += $(common_cflags)
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/upstream-netbsd/include/
 LOCAL_MODULE := grep
 LOCAL_POST_INSTALL_CMD := $(hide) $(foreach t,egrep fgrep,ln -sf grep $(TARGET_OUT)/bin/$(t);)
 include $(BUILD_EXECUTABLE)