diff --git a/evutil.c b/evutil.c
index 7e392790..b6634591 100644
--- a/evutil.c
+++ b/evutil.c
@@ -88,7 +88,7 @@
 #endif
 
 int
-evutil_open_closeonexec(const char *pathname, int flags, mode_t mode)
+evutil_open_closeonexec(const char *pathname, int flags, unsigned mode)
 {
 	int fd;
 
@@ -96,7 +96,10 @@ evutil_open_closeonexec(const char *pathname, int flags, mode_t mode)
 	flags |= O_CLOEXEC;
 #endif
 
-	fd = open(pathname, flags, mode);
+	if (flags & O_CREAT)
+		fd = open(pathname, flags, (mode_t)mode);
+	else
+		fd = open(pathname, flags);
 	if (fd < 0)
 		return -1;
 
diff --git a/util-internal.h b/util-internal.h
index d09aa471..47fe962d 100644
--- a/util-internal.h
+++ b/util-internal.h
@@ -161,7 +161,10 @@ char EVUTIL_TOLOWER(char c);
 #define EVUTIL_UPCAST(ptr, type, field)				\
 	((type *)(((char*)(ptr)) - evutil_offsetof(type, field)))
 
-int evutil_open_closeonexec(const char *pathname, int flags, mode_t mode);
+/* As open(pathname, flags, mode), except that the file is always opened with
+ * the close-on-exec flag set. (And the mode argument is mandatory.)
+ */
+int evutil_open_closeonexec(const char *pathname, int flags, unsigned mode);
 
 int evutil_read_file(const char *filename, char **content_out, size_t *len_out,
     int is_binary);