diff --git a/NEWS.md b/NEWS.md
index c7537eb..735321a 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,10 @@
 # distributional (development version)
 
+## Improvements
+
+* Transformed distributions now work better for monotonic increasing functions 
+  when the domain of the untransformed distribution is R (#129).
+
 ## Breaking changes
 
 * The `quantile()` method for `dist_multivariate_normal()` now defaults to 
diff --git a/R/transformed.R b/R/transformed.R
index 980b601..d9f2ded 100755
--- a/R/transformed.R
+++ b/R/transformed.R
@@ -170,5 +170,5 @@ monotonic_increasing <- function(f, support) {
 
   # Currently assumes (without checking, #9) monotonicity of f over the domain
   x <- f(field(support, "lim")[[1]])
-  isTRUE(x[[2L]] > x[[1L]])
+  isTRUE(x[[2L]] >= x[[1L]])
 }