diff --git a/pymc/distributions/discrete.py b/pymc/distributions/discrete.py
index 44eebdf1ab5..8b1dfb54ccd 100644
--- a/pymc/distributions/discrete.py
+++ b/pymc/distributions/discrete.py
@@ -1063,7 +1063,7 @@ def logcdf(value, lower, upper):
         )
 
     def icdf(value, lower, upper):
-        res = pt.ceil(value * (upper - lower + 1)).astype("int64") + lower - 1
+        res = pt.ceil(value * (upper - lower + 1) + lower - 1).astype("int64")
         res_1m = pt.maximum(res - 1, lower)
         dist = pm.DiscreteUniform.dist(lower=lower, upper=upper)
         value_1m = pt.exp(logcdf(dist, res_1m))