diff --git a/WPrefs.app/Icons.c b/WPrefs.app/Icons.c
index 510a437..72597cf 100644
--- a/WPrefs.app/Icons.c
+++ b/WPrefs.app/Icons.c
@@ -264,8 +264,8 @@ static void createPanel(Panel * p)
 	 * ratio as the screen.
 	 */
 	scr = WMWidgetScreen(panel->parent);
-	swidth = WidthOfScreen(DefaultScreenOfDisplay(WMScreenDisplay(scr)));
-	sheight = HeightOfScreen(DefaultScreenOfDisplay(WMScreenDisplay(scr)));
+	swidth = WMScreenWidth(scr);
+	sheight = WMScreenHeight(scr);
 
 	width = swidth * (122 - 15 * 2) / sheight;
 	if (width <= (240 - 15 * 2)) {
diff --git a/WPrefs.app/WindowHandling.c b/WPrefs.app/WindowHandling.c
index 182dd75..b820b64 100644
--- a/WPrefs.app/WindowHandling.c
+++ b/WPrefs.app/WindowHandling.c
@@ -342,8 +342,8 @@ static void createPanel(Panel * p)
 	 * In this area, we want to have a rectangle with the same aspect
 	 * ratio as the screen.
 	 */
-	swidth = WidthOfScreen(DefaultScreenOfDisplay(WMScreenDisplay(scr)));
-	sheight = HeightOfScreen(DefaultScreenOfDisplay(WMScreenDisplay(scr)));
+	swidth = WMScreenWidth(scr);
+	sheight = WMScreenHeight(scr);
 
 	width = swidth * (109 - 13) / sheight;
 	if (width <= (204 - 13)) {
diff --git a/WPrefs.app/main.c b/WPrefs.app/main.c
index 9793e7b..1ad2edb 100644
--- a/WPrefs.app/main.c
+++ b/WPrefs.app/main.c
@@ -26,6 +26,8 @@
 
 #include <locale.h>
 
+#include <signal.h>
+#include <execinfo.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
@@ -78,6 +80,14 @@ void AddDeadChildHandler(pid_t pid, void (*handler) (void *), void *data)
 	assert(i != MAX_DEATHS);
 }
 
+static void crash_handler(int sig) {
+	void *bt[32];
+	int n = backtrace(bt, 32);
+	fprintf(stderr, "\n=== WPrefs CRASH (signal %d) ===\n", sig);
+	backtrace_symbols_fd(bt, n, STDERR_FILENO);
+	_exit(1);
+}
+
 int main(int argc, char **argv)
 {
 	WMScreen *scr;
@@ -85,6 +95,9 @@ int main(int argc, char **argv)
 	int i;
 	char *display_name = "";
 
+	signal(SIGSEGV, crash_handler);
+	signal(SIGABRT, crash_handler);
+
 	wsetabort(wAbort);
 
 	memset(DeadHandlers, 0, sizeof(DeadHandlers));