diff --git a/src/bases.jl b/src/bases.jl
index 2dbeffc9..fa8770b5 100644
--- a/src/bases.jl
+++ b/src/bases.jl
@@ -28,13 +28,18 @@ n400(; sfreq = 100) = -hanning(0.4, 0.4, sfreq)
 """
 generate a hanning window
 
-duration: in s
-offset: in s, defines hanning peak
+width: in s
+offset: in s, defines hanning peak, must be > round(width/2)
 sfreq: sampling rate in Hz
 """
-function DSP.hanning(duration, offset, sfreq)
-    signal = hanning(Int(round(duration * sfreq)))
-    return pad_array(signal, -Int(round(offset * sfreq / 2)), 0)
+function DSP.hanning(width, offset, sfreq)
+    width = width * sfreq
+    offset = offset * sfreq
+    signal = hanning(Int(round(width)))
+    pad_by = Int(round(offset - length(signal) / 2))
+
+    pad_by < 0 ? error("offset has to be > round(width/2)") : ""
+    return pad_array(signal, -pad_by, 0)
 end
 
 ## pupil
diff --git a/test/bases.jl b/test/bases.jl
index 1ac947a2..6b0ae558 100644
--- a/test/bases.jl
+++ b/test/bases.jl
@@ -1,7 +1,15 @@
 using UnfoldSim
 @testset "hanning" begin
-    @test UnfoldSim.hanning(0.021, 0.04, 1000)[40] == 1.0
+    @test UnfoldSim.hanning(0.021, 0.04, 1000)[41] == 1.0 # why 41 not 40? beacuse round(0.5) = 0 and round(1.5) = 2 -- and we are living on the edge!
     @test UnfoldSim.hanning(0.011, 0.04, 1000)[40] == 1.0
     @test UnfoldSim.hanning(0.011, 0.02, 1000)[20] == 1.0
     @test_throws Exception UnfoldSim.hanning(0.011, 0.0, 1000)
+end
+
+@testset "p100,N170,p300,n400" begin
+    sfreq = 1000
+    @test argmax(p100(; sfreq)) == 0.1 * sfreq
+    @test argmin(n170(; sfreq)) == 0.17 * sfreq
+    @test argmax(p300(; sfreq)) == 0.3 * sfreq
+    @test argmin(n400(; sfreq)) == 0.4 * sfreq
 end
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