diff --git a/src/defaults.c b/src/defaults.c
index 033c3a4..5e1488d 100644
--- a/src/defaults.c
+++ b/src/defaults.c
@@ -163,6 +163,17 @@ static WDECallbackUpdate updateDock;
  * this value */
 #define TOTAL_VALUES_LENGTH	80
 
+/* Return non-zero if file's mtime is newer than the saved timestamp.
+ * Uses nanosecond precision to handle multiple writes within the same
+ * second (e.g., wmsetbg invokes wdwrite twice in rapid succession). */
+#define MTIME_NEWER(stbuf, ts) \
+	((stbuf).st_mtim.tv_sec > (ts).tv_sec || \
+	 ((stbuf).st_mtim.tv_sec == (ts).tv_sec && \
+	  (stbuf).st_mtim.tv_nsec > (ts).tv_nsec))
+
+#define MTIME_FROM_STAT(stbuf) \
+	((struct timespec){ (stbuf).st_mtim.tv_sec, (stbuf).st_mtim.tv_nsec })
+
 #define REFRESH_WINDOW_TEXTURES	(1<<0)
 #define REFRESH_MENU_TEXTURE	(1<<1)
 #define REFRESH_MENU_FONT	(1<<2)
@@ -992,7 +1003,7 @@ WDDomain *wDefaultsInitDomain(const char *domain, Bool requireDictionary)
 				db->dictionary = NULL;
 				wwarning(_("Domain %s (%s) of defaults database is corrupted!"), domain, db->path);
 			}
-			db->timestamp = stbuf.st_mtime;
+			db->timestamp = MTIME_FROM_STAT(stbuf);
 		} else {
 			wwarning(_("could not load domain %s from user defaults database"), domain);
 		}
@@ -1006,12 +1017,12 @@ WDDomain *wDefaultsInitDomain(const char *domain, Bool requireDictionary)
 		WMMergePLDictionaries(shared_dict, db->dictionary, True);
 		WMReleasePropList(db->dictionary);
 		db->dictionary = shared_dict;
-		if (stbuf.st_mtime > db->timestamp)
-			db->timestamp = stbuf.st_mtime;
+		if (MTIME_NEWER(stbuf, db->timestamp))
+			db->timestamp = MTIME_FROM_STAT(stbuf);
 	} else if (!db->dictionary) {
 		db->dictionary = shared_dict;
-		if (stbuf.st_mtime > db->timestamp)
-			db->timestamp = stbuf.st_mtime;
+		if (MTIME_NEWER(stbuf, db->timestamp))
+			db->timestamp = MTIME_FROM_STAT(stbuf);
 	}
 
 	return db;
@@ -1056,8 +1067,8 @@ void wDefaultsCheckDomains(void* arg)
 	/* Parameter not used, but tell the compiler that it is ok */
 	(void) arg;
 
-	if (stat(w_global.domain.wmaker->path, &stbuf) >= 0 && w_global.domain.wmaker->timestamp < stbuf.st_mtime) {
-		w_global.domain.wmaker->timestamp = stbuf.st_mtime;
+	if (stat(w_global.domain.wmaker->path, &stbuf) >= 0 && MTIME_NEWER(stbuf, w_global.domain.wmaker->timestamp)) {
+		w_global.domain.wmaker->timestamp = MTIME_FROM_STAT(stbuf);
 
 		/* Global dictionary */
 		shared_dict = readGlobalDomain("WindowMaker", True);
@@ -1099,7 +1110,7 @@ void wDefaultsCheckDomains(void* arg)
 
 	}
 
-	if (stat(w_global.domain.window_attr->path, &stbuf) >= 0 && w_global.domain.window_attr->timestamp < stbuf.st_mtime) {
+	if (stat(w_global.domain.window_attr->path, &stbuf) >= 0 && MTIME_NEWER(stbuf, w_global.domain.window_attr->timestamp)) {
 		/* global dictionary */
 		shared_dict = readGlobalDomain("WMWindowAttributes", True);
 		/* user dictionary */
@@ -1138,12 +1149,12 @@ void wDefaultsCheckDomains(void* arg)
 			wwarning(_("could not load domain %s from user defaults database"), "WMWindowAttributes");
 		}
 
-		w_global.domain.window_attr->timestamp = stbuf.st_mtime;
+		w_global.domain.window_attr->timestamp = MTIME_FROM_STAT(stbuf);
 		if (shared_dict)
 			WMReleasePropList(shared_dict);
 	}
 
-	if (stat(w_global.domain.root_menu->path, &stbuf) >= 0 && w_global.domain.root_menu->timestamp < stbuf.st_mtime) {
+	if (stat(w_global.domain.root_menu->path, &stbuf) >= 0 && MTIME_NEWER(stbuf, w_global.domain.root_menu->timestamp)) {
 		dict = WMReadPropListFromFile(w_global.domain.root_menu->path);
 		if (dict) {
 			if (!WMIsPLArray(dict) && !WMIsPLString(dict)) {
@@ -1161,7 +1172,7 @@ void wDefaultsCheckDomains(void* arg)
 		} else {
 			wwarning(_("could not load domain %s from user defaults database"), "WMRootMenu");
 		}
-		w_global.domain.root_menu->timestamp = stbuf.st_mtime;
+		w_global.domain.root_menu->timestamp = MTIME_FROM_STAT(stbuf);
 	}
 #ifndef HAVE_INOTIFY
 	if (!arg)
diff --git a/src/defaults.h b/src/defaults.h
index a03ff34..6514f07 100644
--- a/src/defaults.h
+++ b/src/defaults.h
@@ -25,7 +25,7 @@ typedef struct WDDomain {
 	const char *domain_name;
 	WMPropList *dictionary;
 	const char *path;
-	time_t timestamp;
+	struct timespec timestamp;
 } WDDomain;
 
 WDDomain * wDefaultsInitDomain(const char *domain, Bool requireDictionary);
diff --git a/src/rootmenu.c b/src/rootmenu.c
index 765dfeb..b8f5510 100644
--- a/src/rootmenu.c
+++ b/src/rootmenu.c
@@ -1458,7 +1458,7 @@ WMenu *configureMenu(WScreen *scr, WMPropList *definition)
 
 		if (!scr->root_menu || stat_buf.st_mtime > scr->root_menu->timestamp
 		    /* if the pointer in WMRootMenu has changed */
-		    || w_global.domain.root_menu->timestamp > scr->root_menu->timestamp) {
+		    || w_global.domain.root_menu->timestamp.tv_sec > scr->root_menu->timestamp) {
 			WMPropList *menu_from_file = NULL;
 
 			if (menu_is_default) {
@@ -1476,7 +1476,7 @@ WMenu *configureMenu(WScreen *scr, WMPropList *definition)
 			}
 
 			if (menu)
-				menu->timestamp = WMAX(stat_buf.st_mtime, w_global.domain.root_menu->timestamp);
+				menu->timestamp = WMAX(stat_buf.st_mtime, w_global.domain.root_menu->timestamp.tv_sec);
 		} else {
 			menu = NULL;
 		}
@@ -1615,12 +1615,12 @@ void OpenRootMenu(WScreen * scr, int x, int y, int keyboard)
 	 */
 	if (definition) {
 		if (WMIsPLArray(definition)) {
-			if (!scr->root_menu || w_global.domain.root_menu->timestamp > scr->root_menu->timestamp) {
+			if (!scr->root_menu || w_global.domain.root_menu->timestamp.tv_sec > scr->root_menu->timestamp) {
 				wwarning("rootmenu: configureMenu begin");
 				menu = configureMenu(scr, definition);
 				wwarning("rootmenu: configureMenu done, menu=%p", (void*)menu);
 				if (menu)
-					menu->timestamp = w_global.domain.root_menu->timestamp;
+					menu->timestamp = w_global.domain.root_menu->timestamp.tv_sec;
 
 			} else
 				menu = NULL;