diff --git a/Library/Homebrew/version.rb b/Library/Homebrew/version.rb
index e6568a5181..ea9015481a 100644
--- a/Library/Homebrew/version.rb
+++ b/Library/Homebrew/version.rb
@@ -261,7 +261,7 @@ class Version
     # e.g. foobar-4.5.1-1
     # e.g. unrtf_0.20.4-1
     # e.g. ruby-1.9.1-p243
-    m = /[-_]((?:\d+\.)*\d\.\d+-(?:p|rc|RC)?\d+)(?:[-._](?:bin|dist|stable|src|sources))?$/.match(stem)
+    m = /[-_]((?:\d+\.)*\d+\.\d+-(?:p|rc|RC)?\d+)(?:[-._](?:bin|dist|stable|src|sources))?$/.match(stem)
     return m.captures.first unless m.nil?
 
     # URL with no extension
@@ -271,7 +271,7 @@ class Version
     return m.captures.first unless m.nil?
 
     # e.g. lame-398-1
-    m = /-((?:\d)+-\d+)/.match(stem)
+    m = /-(\d+-\d+)/.match(stem)
     return m.captures.first unless m.nil?
 
     # e.g. foobar-4.5.1
@@ -350,7 +350,7 @@ class Version
     # e.g. https://wwwlehre.dhbw-stuttgart.de/~sschulz/WORK/E_DOWNLOAD/V_1.9/E.tgz
     # e.g. https://github.com/JustArchi/ArchiSteamFarm/releases/download/2.3.2.0/ASF.zip
     # e.g. https://people.gnome.org/~newren/eg/download/1.7.5.2/eg
-    m = %r{/([rvV]_?)?(\d\.\d+(\.\d+){,2})}.match(spec_s)
+    m = %r{/([rvV]_?)?(\d+\.\d+(\.\d+){,2})}.match(spec_s)
     return m.captures.second unless m.nil?
 
     # e.g. https://www.ijg.org/files/jpegsrc.v8d.tar.gz