diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.1.1.0 - 2023-02-25
+
+Some values of the Jacobi theta functions were wrong.
+
+
 ## 0.1.0.0 - 2023-02-17
 
-* Initial release.
+Initial release.
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
 # jacobi-theta
 
+<!-- badges: start -->
+[![Check](https://github.com/stla/jacobi-theta/actions/workflows/GithubAction.yml/badge.svg)](https://github.com/stla/jacobi-theta/actions/workflows/GithubAction.yml)
+<!-- badges: end -->
+
 Evaluation of the Jacobi theta functions.
diff --git a/jacobi-theta.cabal b/jacobi-theta.cabal
--- a/jacobi-theta.cabal
+++ b/jacobi-theta.cabal
@@ -1,5 +1,5 @@
 name:                jacobi-theta
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            Jacobi Theta Functions
 description:         Evaluation of the Jacobi theta functions.
 homepage:            https://github.com/stla/jacobi-theta#readme
diff --git a/src/Math/JacobiTheta.hs b/src/Math/JacobiTheta.hs
--- a/src/Math/JacobiTheta.hs
+++ b/src/Math/JacobiTheta.hs
@@ -70,7 +70,7 @@
 
 jtheta1Alt :: Cplx -> Cplx -> Cplx
 jtheta1Alt z tau = 
-  if imagPart tau < 1.3 
+  if imagPart tau > 1.3 
     then
       let w = pi * tau in 
       i_ * jtheta1Alt2 (z / w) (i_ / w) / falpha z tau
diff --git a/tests/Main.hs b/tests/Main.hs
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -12,7 +12,7 @@
 q = exp (-pi)
 
 q' :: Complex Double 
-q' = exp (-pi/100)
+q' = exp (-pi/10)
 
 q'' :: Complex Double 
 q'' = exp (i_ * pi * tau)
@@ -30,7 +30,7 @@
         (approx 10 expected),
 
     testCase "another jtheta1 value" $ do
-      let expected = 0.0284051242069853 :+ 0.0
+      let expected = 1.75929905417707 :+ 0.0
           obtained = jtheta1 2 q'
       assertEqual ""
         (approx 10 obtained)