diff --git a/fakebox/dsp.py b/fakebox/dsp.py
index 7c6ea64..7b6ad20 100644
--- a/fakebox/dsp.py
+++ b/fakebox/dsp.py
@@ -5,10 +5,10 @@
 from fakebox.conf import DEFAULT_SAMPLE_RATE, DEFAULT_BIT_N
 
 DSPFloat = np.float64
-DSPEpislon = DSPFloat(1e-8)
+DSPEpsilon = DSPFloat(1e-8)
 DSPZero = DSPFloat(0.0)
 DSPOne = DSPFloat(1.0)
-DSPOne_L = DSPFloat(1.0) - DSPEpislon
+DSPOne_L = DSPFloat(1.0) - DSPEpsilon
 
 class DSPContext(object):
 
diff --git a/fakebox/stdlib/env.py b/fakebox/stdlib/env.py
index 876abe6..6c7195c 100644
--- a/fakebox/stdlib/env.py
+++ b/fakebox/stdlib/env.py
@@ -1,4 +1,4 @@
-from fakebox.dsp import DSPObj, DSPZero, DSPEpislon
+from fakebox.dsp import DSPObj, DSPZero, DSPEpsilon
 
 class LineSegs(DSPObj):
 
@@ -34,7 +34,7 @@ def _tick(self, ins):
             time_points.append(time_points[-1] + dur)
 
 
-        if running_time > time_points[-1] - DSPEpislon:
+        if running_time > time_points[-1] - DSPEpsilon:
             self.running = False
             return DSPZero