diff --git a/kitty/boss.py b/kitty/boss.py
index ab078bd33..2f132f118 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -1774,8 +1774,8 @@ class Boss:
             else:
                 doit()
 
-    @ac('misc', 'Sleep for the specified time period')
-    def sleep(self, sleep_time: float) -> None:
+    @ac('misc', 'Sleep for the specified time period. Suffix can be s for seconds, m, for minutes, h for hours and d for days. The time can be fractional.')
+    def sleep(self, sleep_time: float = 1.0) -> None:
         sleep(sleep_time)
 
     @ac('misc', 'Click a URL using the keyboard')
diff --git a/kitty/options/utils.py b/kitty/options/utils.py
index 0d5d27009..926aa63df 100644
--- a/kitty/options/utils.py
+++ b/kitty/options/utils.py
@@ -296,6 +296,7 @@ def single_integer_arg(func: str, rest: str) -> FuncArgsType:
 @func_with_args('sleep')
 def sleep(func: str, sleep_time: str) -> FuncArgsType:
     mult = 1
+    sleep_time = sleep_time or '1'
     if sleep_time[-1] in 'shmd':
         mult = {'s': 1, 'm': 60, 'h': 3600, 'd': 24 * 3600}[sleep_time[-1]]
         sleep_time = sleep_time[:-1]