diff --git a/perf/cairo-perf-timer-posix.c b/perf/cairo-perf-timer-posix.c
index 2d91894e7..29fd3fb4a 100644
--- a/perf/cairo-perf-timer-posix.c
+++ b/perf/cairo-perf-timer-posix.c
@@ -63,8 +63,21 @@ alarm_handler (int signal) {
 }
 
 void
-set_alarm (int seconds) {
+set_alarm (double seconds) {
+    struct itimerval tr;
+    long sec, usec;
+
     cairo_perf_alarm_expired = 0;
     signal (SIGALRM, alarm_handler);
-    alarm (seconds);
+
+    sec = floor (seconds);
+    seconds -= sec;
+    usec = seconds * 1e6;
+
+    tr.it_interval.tv_sec  = 0;
+    tr.it_interval.tv_usec = 0;
+    tr.it_value.tv_sec  = sec;
+    tr.it_value.tv_usec = usec;
+
+    setitimer (ITIMER_REAL, &tr, NULL);
 }
diff --git a/perf/cairo-perf-timer-win32.c b/perf/cairo-perf-timer-win32.c
index f3975fa94..c03256def 100644
--- a/perf/cairo-perf-timer-win32.c
+++ b/perf/cairo-perf-timer-win32.c
@@ -64,7 +64,7 @@ alarm_handler (void *closure, DWORD dwTimerLowValue, DWORD dwTimerHighValue) {
 
 HANDLE hTimer = NULL;
 void
-set_alarm (int seconds) {
+set_alarm (double seconds) {
     if (hTimer == NULL)
         hTimer = CreateWaitableTimer(NULL, TRUE, NULL);
     cairo_perf_alarm_expired = 0;
diff --git a/perf/cairo-perf-timer.h b/perf/cairo-perf-timer.h
index bea91c2d3..e9344377b 100644
--- a/perf/cairo-perf-timer.h
+++ b/perf/cairo-perf-timer.h
@@ -60,6 +60,6 @@ void
 alarm_handler (int signal);
 
 void
-set_alarm (int seconds);
+set_alarm (double seconds);
 
 #endif
diff --git a/perf/cairo-perf.c b/perf/cairo-perf.c
index 6c88a6e2b..c750381b7 100644
--- a/perf/cairo-perf.c
+++ b/perf/cairo-perf.c
@@ -27,7 +27,7 @@
 
 #include "cairo-perf.h"
 
-int cairo_perf_duration = 1;
+double cairo_perf_duration = 1;
 
 int cairo_perf_iterations = 10;
 
@@ -134,7 +134,7 @@ main (int argc, char *argv[])
     stats_t stats;
 
     if (getenv("CAIRO_PERF_DURATION"))
-	cairo_perf_duration = strtol(getenv("CAIRO_PERF_DURATION"), NULL, 0);
+	cairo_perf_duration = strtod(getenv("CAIRO_PERF_DURATION"), NULL);
 
     if (getenv("CAIRO_PERF_ITERATIONS"))
 	cairo_perf_iterations = strtol(getenv("CAIRO_PERF_ITERATIONS"), NULL, 0);
diff --git a/perf/cairo-perf.h b/perf/cairo-perf.h
index a913b81f9..aad76e91d 100644
--- a/perf/cairo-perf.h
+++ b/perf/cairo-perf.h
@@ -32,7 +32,7 @@
 
 #include "cairo-perf-timer.h"
 
-extern int cairo_perf_duration;
+extern double cairo_perf_duration;
 extern int cairo_perf_alarm_expired;
 
 #if CAIRO_HAS_WIN32_SURFACE