diff --git a/Param/Distrib/Distributions.cpp b/Param/Distrib/Distributions.cpp
index 2e178c4f7e693a9901fa025dc2700929bc1260a5..c6b74758061abc14763ea349f7e542a2f9a81c5f 100644
--- a/Param/Distrib/Distributions.cpp
+++ b/Param/Distrib/Distributions.cpp
@@ -406,7 +406,7 @@ double DistributionCosine::probabilityDensity(double x) const
         return DoubleEqual(x, m_mean) ? 1.0 : 0.0;
     if (std::abs(x - m_mean) > M_PI * m_hwhm)
         return 0.0;
-    return (1.0 + std::cos(((x - m_mean) / m_hwhm) * (M_PI / 2))) / 2;
+    return (1.0 + std::cos(((x - m_mean) / m_hwhm) * (M_PI / 2))) / (4 * m_hwhm);
 }
 
 bool DistributionCosine::isDelta() const