diff --git a/Android.mk b/Android.mk
index aaae6a0a..80114124 100644
--- a/Android.mk
+++ b/Android.mk
@@ -93,7 +93,7 @@ endif
 endif
 
 LOCAL_CFLAGS += -DRECOVERY_API_VERSION=$(RECOVERY_API_VERSION)
-LOCAL_CFLAGS += -Wno-unused-parameter -Werror
+LOCAL_CFLAGS += -Wall -Wno-unused-parameter -Werror
 
 ifneq ($(TARGET_RECOVERY_UI_MARGIN_HEIGHT),)
 LOCAL_CFLAGS += -DRECOVERY_UI_MARGIN_HEIGHT=$(TARGET_RECOVERY_UI_MARGIN_HEIGHT)
@@ -204,7 +204,7 @@ LOCAL_SRC_FILES := \
     rotate_logs.cpp
 LOCAL_MODULE := recovery-persist
 LOCAL_SHARED_LIBRARIES := liblog libbase
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_INIT_RC := recovery-persist.rc
 include $(BUILD_EXECUTABLE)
 
@@ -216,7 +216,7 @@ LOCAL_SRC_FILES := \
     rotate_logs.cpp
 LOCAL_MODULE := recovery-refresh
 LOCAL_SHARED_LIBRARIES := liblog libbase
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_INIT_RC := recovery-refresh.rc
 include $(BUILD_EXECUTABLE)
 
@@ -231,13 +231,14 @@ LOCAL_STATIC_LIBRARIES := \
     libcrypto_utils \
     libcrypto \
     libbase
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_STATIC_LIBRARY)
 
 # Wear default device
 # ===============================
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := wear_device.cpp
+LOCAL_CFLAGS := -Wall -Werror
 
 # Should match TARGET_RECOVERY_UI_LIB in BoardConfig.mk.
 LOCAL_MODULE := librecovery_ui_wear
@@ -249,6 +250,7 @@ include $(BUILD_STATIC_LIBRARY)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := vr_device.cpp
+LOCAL_CFLAGS := -Wall -Werror
 
 # should match TARGET_RECOVERY_UI_LIB set in BoardConfig.mk
 LOCAL_MODULE := librecovery_ui_vr
diff --git a/applypatch/Android.mk b/applypatch/Android.mk
index e38207c2..59aa0ce6 100644
--- a/applypatch/Android.mk
+++ b/applypatch/Android.mk
@@ -37,6 +37,7 @@ LOCAL_STATIC_LIBRARIES := \
     libz
 LOCAL_CFLAGS := \
     -DZLIB_CONST \
+    -Wall \
     -Werror
 include $(BUILD_STATIC_LIBRARY)
 
@@ -59,6 +60,7 @@ LOCAL_STATIC_LIBRARIES := \
     libz
 LOCAL_CFLAGS := \
     -DZLIB_CONST \
+    -Wall \
     -Werror
 include $(BUILD_STATIC_LIBRARY)
 
@@ -82,6 +84,7 @@ LOCAL_STATIC_LIBRARIES := \
     libz
 LOCAL_CFLAGS := \
     -DZLIB_CONST \
+    -Wall \
     -Werror
 include $(BUILD_HOST_STATIC_LIBRARY)
 
@@ -97,7 +100,7 @@ LOCAL_STATIC_LIBRARIES := \
     libbase \
     libedify \
     libcrypto
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_STATIC_LIBRARY)
 
 # applypatch (target executable)
@@ -119,13 +122,14 @@ LOCAL_SHARED_LIBRARIES := \
     libbase \
     libz \
     libcutils
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 include $(BUILD_EXECUTABLE)
 
 libimgdiff_src_files := imgdiff.cpp
 
 # libbsdiff is compiled with -D_FILE_OFFSET_BITS=64.
 libimgdiff_cflags := \
+    -Wall \
     -Werror \
     -D_FILE_OFFSET_BITS=64 \
     -DZLIB_CONST
@@ -177,7 +181,7 @@ include $(BUILD_HOST_STATIC_LIBRARY)
 include $(CLEAR_VARS)
 LOCAL_SRC_FILES := imgdiff_main.cpp
 LOCAL_MODULE := imgdiff
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_STATIC_LIBRARIES := \
     libimgdiff \
     $(libimgdiff_static_libraries) \
diff --git a/bootloader_message/Android.bp b/bootloader_message/Android.bp
index f0d76e71..456b04c3 100644
--- a/bootloader_message/Android.bp
+++ b/bootloader_message/Android.bp
@@ -17,7 +17,10 @@
 cc_library_static {
     name: "libbootloader_message",
     srcs: ["bootloader_message.cpp"],
-    cppflags: ["-Werror"],
+    cppflags: [
+        "-Wall",
+        "-Werror",
+    ],
     static_libs: [
         "libbase",
         "libfs_mgr",
diff --git a/minui/Android.mk b/minui/Android.mk
index 4dfc65f8..92469849 100644
--- a/minui/Android.mk
+++ b/minui/Android.mk
@@ -32,7 +32,7 @@ LOCAL_STATIC_LIBRARIES := \
     libpng \
     libbase
 
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 
@@ -68,7 +68,7 @@ LOCAL_SHARED_LIBRARIES := \
     libpng \
     libbase
 
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
 LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
 include $(BUILD_SHARED_LIBRARY)
diff --git a/otafault/Android.mk b/otafault/Android.mk
index 7b5aab0b..4784d56e 100644
--- a/otafault/Android.mk
+++ b/otafault/Android.mk
@@ -24,6 +24,7 @@ otafault_static_libs := \
     liblog
 
 LOCAL_CFLAGS := \
+    -Wall \
     -Werror \
     -Wthread-safety \
     -Wthread-safety-negative \
@@ -46,7 +47,7 @@ LOCAL_SRC_FILES := config.cpp ota_io.cpp test.cpp
 LOCAL_MODULE_TAGS := tests
 LOCAL_MODULE := otafault_test
 LOCAL_STATIC_LIBRARIES := $(otafault_static_libs)
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_C_INCLUDES := bootable/recovery
 LOCAL_FORCE_STATIC_EXECUTABLE := true
 
diff --git a/otafault/config.cpp b/otafault/config.cpp
index 8590833e..b94e429c 100644
--- a/otafault/config.cpp
+++ b/otafault/config.cpp
@@ -69,7 +69,9 @@ std::string fault_fname(const char* io_type) {
     fname.resize(OTAIO_MAX_FNAME_SIZE);
     ZipString zip_type_path(type_path.c_str());
     ZipEntry entry;
-    int status = FindEntry(archive, zip_type_path, &entry);
+    if (FindEntry(archive, zip_type_path, &entry) != 0) {
+        return {};
+    }
     ExtractToMemory(archive, &entry, reinterpret_cast<uint8_t*>(&fname[0]), OTAIO_MAX_FNAME_SIZE);
     return fname;
 }
diff --git a/print_sha1.h b/print_sha1.h
index 1f858951..d0c18b35 100644
--- a/print_sha1.h
+++ b/print_sha1.h
@@ -32,15 +32,15 @@ static std::string print_sha1(const uint8_t* sha1, size_t len) {
     return result;
 }
 
-static std::string print_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
+[[maybe_unused]] static std::string print_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
     return print_sha1(sha1, SHA_DIGEST_LENGTH);
 }
 
-static std::string short_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
+[[maybe_unused]] static std::string short_sha1(const uint8_t sha1[SHA_DIGEST_LENGTH]) {
     return print_sha1(sha1, 4);
 }
 
-static std::string print_hex(const uint8_t* bytes, size_t len) {
+[[maybe_unused]] static std::string print_hex(const uint8_t* bytes, size_t len) {
     return print_sha1(bytes, len);
 }
 
diff --git a/tests/Android.mk b/tests/Android.mk
index f2497b8b..748d9c87 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -18,7 +18,7 @@ LOCAL_PATH := $(call my-dir)
 
 # Unit tests
 include $(CLEAR_VARS)
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE := recovery_unit_test
 LOCAL_COMPATIBILITY_SUITE := device-tests
 LOCAL_STATIC_LIBRARIES := \
@@ -46,7 +46,7 @@ include $(BUILD_NATIVE_TEST)
 
 # Manual tests
 include $(CLEAR_VARS)
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE := recovery_manual_test
 LOCAL_STATIC_LIBRARIES := \
     libminui \
@@ -81,6 +81,7 @@ include $(BUILD_NATIVE_TEST)
 # Component tests
 include $(CLEAR_VARS)
 LOCAL_CFLAGS := \
+    -Wall \
     -Werror \
     -D_FILE_OFFSET_BITS=64
 
@@ -191,7 +192,7 @@ include $(BUILD_NATIVE_TEST)
 
 # Host tests
 include $(CLEAR_VARS)
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_MODULE := recovery_host_test
 LOCAL_MODULE_HOST_OS := linux
 LOCAL_C_INCLUDES := bootable/recovery
diff --git a/tests/component/applypatch_test.cpp b/tests/component/applypatch_test.cpp
index 016fed9b..42542898 100644
--- a/tests/component/applypatch_test.cpp
+++ b/tests/component/applypatch_test.cpp
@@ -61,14 +61,6 @@ static void mangle_file(const std::string& fname) {
   ASSERT_TRUE(android::base::WriteStringToFile(content, fname));
 }
 
-static bool file_cmp(const std::string& f1, const std::string& f2) {
-  std::string c1;
-  android::base::ReadFileToString(f1, &c1);
-  std::string c2;
-  android::base::ReadFileToString(f2, &c2);
-  return c1 == c2;
-}
-
 class ApplyPatchTest : public ::testing::Test {
  public:
   static void SetUpTestCase() {
diff --git a/uncrypt/Android.mk b/uncrypt/Android.mk
index cb60c721..a3b0ca98 100644
--- a/uncrypt/Android.mk
+++ b/uncrypt/Android.mk
@@ -25,7 +25,7 @@ LOCAL_STATIC_LIBRARIES := \
     liblog \
     libfs_mgr \
     libcutils
-LOCAL_CFLAGS := -Werror
+LOCAL_CFLAGS := -Wall -Werror
 LOCAL_INIT_RC := uncrypt.rc
 
 include $(BUILD_EXECUTABLE)
diff --git a/updater/Android.mk b/updater/Android.mk
index 86dc48e3..12181602 100644
--- a/updater/Android.mk
+++ b/updater/Android.mk
@@ -66,6 +66,7 @@ LOCAL_C_INCLUDES := \
     external/e2fsprogs/misc
 
 LOCAL_CFLAGS := \
+    -Wall \
     -Wno-unused-parameter \
     -Werror
 
@@ -91,6 +92,7 @@ LOCAL_C_INCLUDES := \
     $(LOCAL_PATH)/include
 
 LOCAL_CFLAGS := \
+    -Wall \
     -Wno-unused-parameter \
     -Werror
 
diff --git a/wear_ui.cpp b/wear_ui.cpp
index e4806718..85c8f835 100644
--- a/wear_ui.cpp
+++ b/wear_ui.cpp
@@ -39,13 +39,6 @@
 #include "common.h"
 #include "device.h"
 
-// Return the current time as a double (including fractions of a second).
-static double now() {
-  struct timeval tv;
-  gettimeofday(&tv, NULL);
-  return tv.tv_sec + tv.tv_usec / 1000000.0;
-}
-
 WearRecoveryUI::WearRecoveryUI()
     : kProgressBarBaseline(RECOVERY_UI_PROGRESS_BAR_BASELINE),
       kMenuUnusableRows(RECOVERY_UI_MENU_UNUSABLE_ROWS) {
@@ -167,7 +160,6 @@ void WearRecoveryUI::draw_screen_locked() {
     // display from the bottom up, until we hit the top of the
     // screen, the bottom of the menu, or we've displayed the
     // entire text buffer.
-    int ty;
     int row = (text_top_ + text_rows_ - 1) % text_rows_;
     size_t count = 0;
     for (int ty = gr_fb_height() - char_height_ - kMarginHeight; ty > y + 2 && count < text_rows_;