diff --git a/src/libopensc/log.c b/src/libopensc/log.c
index 521d510c..00ed8142 100644
--- a/src/libopensc/log.c
+++ b/src/libopensc/log.c
@@ -84,7 +84,7 @@ void sc_do_log_va(sc_context_t *ctx, int level, const char *file, int line, cons
 	gettimeofday (&tv, NULL);
 	tm = localtime (&tv.tv_sec);
 	strftime (time_string, sizeof(time_string), "%H:%M:%S", tm);
-	r = snprintf(p, left, "0x%lx %s.%03ld ", (unsigned long)pthread_self(), time_string, tv.tv_usec / 1000);
+	r = snprintf(p, left, "0x%lx %s.%03d ", (unsigned long)pthread_self(), time_string, tv.tv_usec / 1000);
 #endif
 	p += r;
 	left -= r;