diff --git a/src/c2.c b/src/c2.c
index f2db608..457ee3d 100644
--- a/src/c2.c
+++ b/src/c2.c
@@ -249,7 +249,7 @@ static inline int strcmp_wd(const char *needle, const char *src) {
 /**
  * Return whether a c2_ptr_t is empty.
  */
-static inline bool c2_ptr_isempty(const c2_ptr_t p) {
+static inline attr_unused bool c2_ptr_isempty(const c2_ptr_t p) {
 	return !(p.isbranch ? (bool)p.b : (bool)p.l);
 }
 
diff --git a/src/opengl.h b/src/opengl.h
index fd3fe9c..5ef58c4 100644
--- a/src/opengl.h
+++ b/src/opengl.h
@@ -134,7 +134,7 @@ static inline bool ensure_glx_context(session_t *ps) {
 /**
  * Free a GLX texture.
  */
-static inline void free_texture_r(session_t *ps, GLuint *ptexture) {
+static inline void free_texture_r(session_t *ps attr_unused, GLuint *ptexture) {
 	if (*ptexture) {
 		assert(glx_has_context(ps));
 		glDeleteTextures(1, ptexture);
diff --git a/src/utils.h b/src/utils.h
index 104bcca..e6feaac 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -57,7 +57,7 @@ safe_isnan(double a) {
 /// being always true or false.
 #define ASSERT_IN_RANGE(var, lower, upper)                                               \
 	do {                                                                             \
-		auto __tmp = (var);                                                      \
+		auto __tmp attr_unused = (var);                                          \
 		_Pragma("GCC diagnostic push");                                          \
 		_Pragma("GCC diagnostic ignored \"-Wtype-limits\"");                     \
 		assert(__tmp >= lower);                                                  \
@@ -69,7 +69,7 @@ safe_isnan(double a) {
 /// being always true or false.
 #define ASSERT_GEQ(var, lower)                                                           \
 	do {                                                                             \
-		auto __tmp = (var);                                                      \
+		auto __tmp attr_unused = (var);                                          \
 		_Pragma("GCC diagnostic push");                                          \
 		_Pragma("GCC diagnostic ignored \"-Wtype-limits\"");                     \
 		assert(__tmp >= lower);                                                  \
@@ -111,7 +111,7 @@ safe_isnan(double a) {
 #define to_u32_checked(val)                                                              \
 	({                                                                               \
 		auto tmp = (val);                                                        \
-		int64_t max = UINT32_MAX; /* silence clang tautological                  \
+		int64_t max attr_unused = UINT32_MAX; /* silence clang tautological      \
 		                                         comparison warning*/            \
 		ASSERT_IN_RANGE(tmp, 0, max);                                            \
 		(uint32_t) tmp;                                                          \
diff --git a/src/win.c b/src/win.c
index fd247be..d0be605 100644
--- a/src/win.c
+++ b/src/win.c
@@ -329,8 +329,7 @@ void win_release_images(struct backend_base *backend, struct managed_win *w) {
 void win_process_flags(session_t *ps, struct managed_win *w) {
 	// Make sure all pending window updates are processed before this. Making this
 	// assumption simplifies some checks (e.g. whether window is mapped)
-	auto iw = (struct managed_win_internal *)w;
-	assert(iw->pending_updates == 0);
+	assert(((struct managed_win_internal *)w)->pending_updates == 0);
 
 	if (!w->flags || (w->flags & WIN_FLAGS_IMAGE_ERROR) != 0) {
 		return;
@@ -2250,6 +2249,7 @@ win_is_fullscreen_xcb(xcb_connection_t *c, const struct atom *a, const xcb_windo
 void win_queue_update(struct managed_win *_w, enum win_update update) {
 	auto w = (struct managed_win_internal *)_w;
 	assert(popcount(update) == 1);
+	assert(update == WIN_UPDATE_MAP);        // Currently the only supported update
 
 	if (unlikely(_w->state == WSTATE_DESTROYING)) {
 		log_error("Updates queued on a destroyed window %#010x (%s)", _w->base.id,
@@ -2257,7 +2257,7 @@ void win_queue_update(struct managed_win *_w, enum win_update update) {
 		return;
 	}
 
-	w->pending_updates |= WIN_UPDATE_MAP;
+	w->pending_updates |= update;
 }
 
 /// Process pending updates on a window. Has to be called in X critical section