diff --git a/benchmarks/Android.mk b/benchmarks/Android.mk
index cf3d692..f9722ae 100644
--- a/benchmarks/Android.mk
+++ b/benchmarks/Android.mk
@@ -24,7 +24,7 @@
 
 benchmark_c_flags = \
     -O2 \
-    -Wall -Wextra \
+    -Wall -Wextra -Wunused \
     -Werror \
     -fno-builtin \
     -std=gnu++11 \
diff --git a/libc/Android.mk b/libc/Android.mk
index 4783bd3..02fad3b 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -486,7 +486,7 @@
 # ========================================================
 libc_common_cflags := \
     -D_LIBC=1 \
-    -Wall -Wextra \
+    -Wall -Wextra -Wunused \
 
 # Try to catch typical 32-bit assumptions that break with 64-bit pointers.
 libc_common_cflags += \
@@ -709,7 +709,7 @@
 LOCAL_SRC_FILES := $(libc_upstream_openbsd_src_files)
 LOCAL_CFLAGS := \
     $(libc_common_cflags) \
-    -Wno-sign-compare -Wno-uninitialized \
+    -Wno-sign-compare -Wno-uninitialized -Wno-unused-parameter \
     -Werror \
     -I$(LOCAL_PATH)/upstream-openbsd/android/include \
     -I$(LOCAL_PATH)/upstream-openbsd/lib/libc/include \
diff --git a/libc/bionic/libc_init_dynamic.cpp b/libc/bionic/libc_init_dynamic.cpp
index 659cf39..7c46364 100644
--- a/libc/bionic/libc_init_dynamic.cpp
+++ b/libc/bionic/libc_init_dynamic.cpp
@@ -94,7 +94,7 @@
 // Note that the dynamic linker has also run all constructors in the
 // executable at this point.
 __noreturn void __libc_init(void* raw_args,
-                            void (*onexit)(void),
+                            void (*onexit)(void) __unused,
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
 
diff --git a/libc/bionic/libc_init_static.cpp b/libc/bionic/libc_init_static.cpp
index e45422e..ab0b3a6 100644
--- a/libc/bionic/libc_init_static.cpp
+++ b/libc/bionic/libc_init_static.cpp
@@ -85,7 +85,7 @@
 }
 
 __noreturn void __libc_init(void* raw_args,
-                            void (*onexit)(void),
+                            void (*onexit)(void) __unused,
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
   KernelArgumentBlock args(raw_args);
diff --git a/libdl/Android.mk b/libdl/Android.mk
index 3d60474..cb1cb7d 100644
--- a/libdl/Android.mk
+++ b/libdl/Android.mk
@@ -22,7 +22,7 @@
 LOCAL_LDFLAGS_x86_64 := $(LOCAL_LDFLAGS_x86)
 
 LOCAL_SRC_FILES:= libdl.c
-LOCAL_CFLAGS := -Wall -Wextra -Werror
+LOCAL_CFLAGS := -Wall -Wextra -Wunused -Werror
 
 LOCAL_MODULE := libdl
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
diff --git a/linker/Android.mk b/linker/Android.mk
index d2bcfaf..811cf6e 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -26,7 +26,7 @@
     -fno-stack-protector \
     -Wstrict-overflow=5 \
     -fvisibility=hidden \
-    -Wall -Wextra -Werror \
+    -Wall -Wextra -Wunused -Werror \
 
 LOCAL_CONLYFLAGS += \
     -std=gnu99 \
diff --git a/linker/linked_list.h b/linker/linked_list.h
index a6bea6c..52af0f1 100644
--- a/linker/linked_list.h
+++ b/linker/linked_list.h
@@ -59,7 +59,6 @@
 
   template<typename F>
   void remove_if(F&& predicate) {
-    LinkedListEntry<T>* e = head_;
     for (LinkedListEntry<T>* e = head_; e != nullptr; e = e->next) {
       if (e->element != nullptr && predicate(e->element)) {
         e->element = nullptr;
diff --git a/linker/linker.cpp b/linker/linker.cpp
index 98cb178..5452f30 100644
--- a/linker/linker.cpp
+++ b/linker/linker.cpp
@@ -827,7 +827,7 @@
   }
 }
 
-soinfo* do_dlopen(const char* name, int flags, soinfo* caller, const android_dlextinfo* extinfo) {
+soinfo* do_dlopen(const char* name, int flags, soinfo* /*caller*/, const android_dlextinfo* extinfo) {
   if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL|RTLD_NOLOAD)) != 0) {
     DL_ERR("invalid flags to dlopen: %x", flags);
     return NULL;
diff --git a/linker/tests/Android.mk b/linker/tests/Android.mk
index 831cfcb..683f9ee 100644
--- a/linker/tests/Android.mk
+++ b/linker/tests/Android.mk
@@ -26,7 +26,7 @@
 
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 
-LOCAL_CFLAGS += -g -Wall -Wextra -Werror -std=gnu++11
+LOCAL_CFLAGS += -g -Wall -Wextra -Wunused -Werror -std=gnu++11
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../libc/
 
 LOCAL_SRC_FILES := \
diff --git a/tests/Android.mk b/tests/Android.mk
index db8dd8c..811c12a 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -34,7 +34,7 @@
 test_cflags = \
     -fstack-protector-all \
     -g \
-    -Wall -Wextra \
+    -Wall -Wextra -Wunused \
     -Werror \
     -fno-builtin \