diff --git a/Library/Homebrew/brew.sh b/Library/Homebrew/brew.sh
index dd2c96f3f3..011f643dc2 100644
--- a/Library/Homebrew/brew.sh
+++ b/Library/Homebrew/brew.sh
@@ -100,8 +100,9 @@ then
   # This is i386 even on x86_64 machines
   [[ "$HOMEBREW_PROCESSOR" = "i386" ]] && HOMEBREW_PROCESSOR="Intel"
   HOMEBREW_MACOS_VERSION="$(/usr/bin/sw_vers -productVersion)"
-  # Don't change this from OS X to match what macOS itself does
-  HOMEBREW_OS_VERSION="OS X $HOMEBREW_MACOS_VERSION"
+  HOMEBREW_OS_VERSION="macOS $HOMEBREW_MACOS_VERSION"
+  # Don't change this from Mac OS X to match what macOS itself does in Safari on 10.12
+  HOMEBREW_OS_USER_AGENT_VERSION="Mac OS X $HOMEBREW_MACOS_VERSION"
 
   printf -v HOMEBREW_MACOS_VERSION_NUMERIC "%02d%02d%02d" ${HOMEBREW_MACOS_VERSION//./ }
   if [[ "$HOMEBREW_MACOS_VERSION_NUMERIC" -lt "100900" &&
@@ -114,8 +115,9 @@ else
   HOMEBREW_PRODUCT="${HOMEBREW_SYSTEM}brew"
   [[ -n "$HOMEBREW_LINUX" ]] && HOMEBREW_OS_VERSION="$(lsb_release -sd 2>/dev/null)"
   : "${HOMEBREW_OS_VERSION:=$(uname -r)}"
+  HOMEBREW_OS_USER_AGENT_VERSION="$HOMEBREW_OS_VERSION"
 fi
-HOMEBREW_USER_AGENT="$HOMEBREW_PRODUCT/$HOMEBREW_USER_AGENT_VERSION ($HOMEBREW_SYSTEM; $HOMEBREW_PROCESSOR $HOMEBREW_OS_VERSION)"
+HOMEBREW_USER_AGENT="$HOMEBREW_PRODUCT/$HOMEBREW_USER_AGENT_VERSION ($HOMEBREW_SYSTEM; $HOMEBREW_PROCESSOR $HOMEBREW_OS_USER_AGENT_VERSION)"
 HOMEBREW_CURL_VERSION="$("$HOMEBREW_CURL" --version 2>/dev/null | head -n1 | /usr/bin/awk '{print $1"/"$2}')"
 HOMEBREW_USER_AGENT_CURL="$HOMEBREW_USER_AGENT $HOMEBREW_CURL_VERSION"