diff --git a/base/libc.jl b/base/libc.jl
index e78b5a1d13c92..1ffe8a92aabfb 100644
--- a/base/libc.jl
+++ b/base/libc.jl
@@ -122,6 +122,16 @@ elseif Sys.iswindows()
 else
     error("systemsleep undefined for this OS")
 end
+"""
+    systemsleep(s::Real)
+
+Suspends execution for `s` seconds.
+This function does not yield to Julia's scheduler and therefore blocks
+the Julia thread that it is running on for the duration of the sleep time.
+
+See also: [`sleep`](@ref)
+"""
+systemsleep
 
 struct TimeVal
    sec::Int64
diff --git a/doc/src/base/libc.md b/doc/src/base/libc.md
index 65bdb3da10d28..0af1b74a79a71 100644
--- a/doc/src/base/libc.md
+++ b/doc/src/base/libc.md
@@ -14,4 +14,5 @@ Base.Libc.strftime
 Base.Libc.strptime
 Base.Libc.TmStruct
 Base.Libc.flush_cstdio
+Base.Libc.systemsleep
 ```