diff --git a/Library/Homebrew/extend/os/mac/extend/ENV/std.rb b/Library/Homebrew/extend/os/mac/extend/ENV/std.rb
index ae04e62a8d..11287c3167 100644
--- a/Library/Homebrew/extend/os/mac/extend/ENV/std.rb
+++ b/Library/Homebrew/extend/os/mac/extend/ENV/std.rb
@@ -52,7 +52,7 @@ module Stdenv
   def remove_macosxsdk(version = nil)
     # Clear all lib and include dirs from CFLAGS, CPPFLAGS, LDFLAGS that were
     # previously added by macosxsdk
-    remove_from_cflags(/ ?-mmacosx-version-min=10\.\d+/)
+    remove_from_cflags(/ ?-mmacosx-version-min=\d+\.\d+/)
     delete("CPATH")
     remove "LDFLAGS", "-L#{HOMEBREW_PREFIX}/lib"
 
diff --git a/Library/Homebrew/os/mac.rb b/Library/Homebrew/os/mac.rb
index 654f2d5c04..f559bfacf9 100644
--- a/Library/Homebrew/os/mac.rb
+++ b/Library/Homebrew/os/mac.rb
@@ -21,7 +21,7 @@ module OS
     # This can be compared to numerics, strings, or symbols
     # using the standard Ruby Comparable methods.
     def version
-      @version ||= Version.new(full_version.to_s[/10\.\d+/])
+      @version ||= Version.new(full_version.to_s[/^\d+\.\d+/])
     end
 
     # This can be compared to numerics, strings, or symbols
diff --git a/Library/Homebrew/shims/super/cc b/Library/Homebrew/shims/super/cc
index b6249a04f4..4462deae26 100755
--- a/Library/Homebrew/shims/super/cc
+++ b/Library/Homebrew/shims/super/cc
@@ -188,8 +188,8 @@ class Cmd
     when "-Xpreprocessor", "-Xclang"
       # used for -Xpreprocessor -fopenmp
       args << arg << enum.next
-    when /-mmacosx-version-min=10\.(\d+)/
-      arg = "-mmacosx-version-min=10.9" if high_sierra_or_later? && $1.to_i < 9
+    when /-mmacosx-version-min=(\d+)\.(\d+)/
+      arg = "-mmacosx-version-min=10.9" if high_sierra_or_later? && $1 == "10" && $2.to_i < 9
       args << arg
     when "--fast-math"
       arg = "-ffast-math" if tool =~ /^clang/