diff --git a/src/OpenFOAM/distributions/standardNormal/standardNormal.C b/src/OpenFOAM/distributions/standardNormal/standardNormal.C
index d2f2e611ea..fa5b0893a1 100644
--- a/src/OpenFOAM/distributions/standardNormal/standardNormal.C
+++ b/src/OpenFOAM/distributions/standardNormal/standardNormal.C
@@ -57,7 +57,7 @@ Foam::tmp<Foam::scalarField> Foam::distributions::standardNormal::approxErf
 
 Foam::scalar Foam::distributions::standardNormal::approxErfInv(const scalar y)
 {
-    const scalar l = log(1 - y*y), b = 2/(pi*a_) + l/2;
+    const scalar l = log(Foam::max(1 - y*y, small/2)), b = 2/(pi*a_) + l/2;
     return sign(y)*sqrt(-b + sqrt(b*b - l/a_));
 }