diff --git a/libc/calls/calls.h b/libc/calls/calls.h
index 53565d129..e97ad0011 100644
--- a/libc/calls/calls.h
+++ b/libc/calls/calls.h
@@ -168,7 +168,7 @@ int truncate(const char *, int64_t);
 int ttyname_r(int, char *, size_t);
 int unlink(const char *);
 int unlinkat(int, const char *, int);
-int usleep(unsigned);
+int usleep(uint64_t);
 int vfork(void) returnstwice;
 int wait(int *);
 int waitpid(int, int *, int);
diff --git a/libc/calls/usleep.c b/libc/calls/usleep.c
index 15c37d1d0..abd8b490b 100644
--- a/libc/calls/usleep.c
+++ b/libc/calls/usleep.c
@@ -19,6 +19,7 @@
 #include "libc/calls/struct/timespec.h"
 #include "libc/errno.h"
 #include "libc/sysv/consts/clock.h"
+#include "libc/sysv/consts/utime.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/time/time.h"
 
@@ -32,7 +33,7 @@
  * @cancelationpoint
  * @norestart
  */
-int usleep(uint32_t micros) {
+int usleep(uint64_t micros) {
   errno_t err;
   struct timespec ts = timespec_frommicros(micros);
   err = clock_nanosleep(CLOCK_REALTIME, 0, &ts, 0);