diff --git a/sway/commands/output/background.c b/sway/commands/output/background.c
index affa04ea..f65904bb 100644
--- a/sway/commands/output/background.c
+++ b/sway/commands/output/background.c
@@ -1,5 +1,7 @@
-#define _POSIX_C_SOURCE 200809
+#define _POSIX_C_SOURCE 200809L
 #include <libgen.h>
+#include <stdio.h>
+#include <string.h>
 #include <strings.h>
 #include <unistd.h>
 #include <wordexp.h>
@@ -112,8 +114,8 @@ struct cmd_results *output_cmd_background(int argc, char **argv) {
 
 		bool can_access = access(src, F_OK) != -1;
 		if (!can_access) {
-			sway_log(SWAY_ERROR, "Unable to access background file '%s': %s",
-					src, strerror(errno));
+			sway_log_errno(SWAY_ERROR, "Unable to access background file '%s'",
+					src);
 			config_add_swaynag_warning("Unable to access background file '%s'",
 					src);
 			free(src);
diff --git a/sway/desktop/transaction.c b/sway/desktop/transaction.c
index 55cf1c5e..88a9b027 100644
--- a/sway/desktop/transaction.c
+++ b/sway/desktop/transaction.c
@@ -1,6 +1,4 @@
 #define _POSIX_C_SOURCE 200809L
-#include <errno.h>
-#include <limits.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -449,9 +447,8 @@ static void transaction_commit(struct sway_transaction *transaction) {
 			wl_event_source_timer_update(transaction->timer,
 					server.txn_timeout_ms);
 		} else {
-			sway_log(SWAY_ERROR, "Unable to create transaction timer (%s). "
-					"Some imperfect frames might be rendered.",
-					strerror(errno));
+			sway_log_errno(SWAY_ERROR, "Unable to create transaction timer "
+					"(some imperfect frames might be rendered)");
 			transaction->num_waiting = 0;
 		}
 	}
diff --git a/sway/input/seat.c b/sway/input/seat.c
index fd5eda2d..b6ccd830 100644
--- a/sway/input/seat.c
+++ b/sway/input/seat.c
@@ -1,7 +1,6 @@
 #define _POSIX_C_SOURCE 200809L
-#include <assert.h>
-#include <errno.h>
 #include <linux/input-event-codes.h>
+#include <string.h>
 #include <strings.h>
 #include <time.h>
 #include <wlr/types/wlr_cursor.h>
@@ -827,8 +826,7 @@ void seat_set_focus(struct sway_seat *seat, struct sway_node *node) {
 				wl_event_source_timer_update(view->urgent_timer,
 						config->urgent_timeout);
 			} else {
-				sway_log(SWAY_ERROR, "Unable to create urgency timer (%s)",
-						strerror(errno));
+				sway_log_errno(SWAY_ERROR, "Unable to create urgency timer");
 				handle_urgent_timeout(view);
 			}
 		} else {