diff --git a/lib/pure/math.nim b/lib/pure/math.nim
index d347006b7..c9f71b64b 100755
--- a/lib/pure/math.nim
+++ b/lib/pure/math.nim
@@ -159,6 +159,7 @@ when not defined(ECMAScript):
     ## same as ``sqrt(x*x + y*y)``.
   
   proc sinh*(x: float): float {.importc: "sinh", header: "<math.h>".}
+  proc sin*(x: float): float {.importc: "sin", header: "<math.h>".}
   proc tan*(x: float): float {.importc: "tan", header: "<math.h>".}
   proc tanh*(x: float): float {.importc: "tanh", header: "<math.h>".}
   proc pow*(x, y: float): float {.importc: "pow", header: "<math.h>".}
@@ -209,6 +210,7 @@ else:
   proc cosh*(x: float): float = return (exp(x)+exp(-x))*0.5
   proc hypot*(x, y: float): float = return sqrt(x*x + y*y)
   proc sinh*(x: float): float = return (exp(x)-exp(-x))*0.5
+  proc sin*(x: float): float {.importc: "Math.sin", nodecl.}  
   proc tan*(x: float): float {.importc: "Math.tan", nodecl.}
   proc tanh*(x: float): float =
     var y = exp(2.0*x)