diff --git a/NEWS.md b/NEWS.md
index 7c881d83..40c85b30 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,8 @@
 # reticulate (development version)
 
+- Fixed an issue where `virtualenv_starter()` would not discover a 
+  custom built Python (#1704).
+
 # reticulate 1.40.0
 
 - The S3 classes for some (rarely encountered) Python objects have changed.
diff --git a/R/virtualenv.R b/R/virtualenv.R
index 2a97a311..53198eb5 100644
--- a/R/virtualenv.R
+++ b/R/virtualenv.R
@@ -551,6 +551,7 @@ virtualenv_starter <- function(version = NULL, all = FALSE) {
             length(v) != 1L ||
             !startsWith(v, "Python "))
           return(NA_character_)
+        v <- sub("\\+.*$", "", v)
         substr(v, 8L, 999L)
       }, error = function(e) NA_character_), ""), strict = FALSE)
     df <- data.frame(version = v, path = p,