diff --git a/gitprompt.sh b/gitprompt.sh
index a534525..e5a4c1d 100755
--- a/gitprompt.sh
+++ b/gitprompt.sh
@@ -3,7 +3,7 @@
 function async_run()
 {
   {
-    $1 &> /dev/null
+    eval "$@" &> /dev/null
   }&
 }
 
@@ -357,13 +357,55 @@ function setGitPrompt() {
   updatePrompt
 }
 
+# some versions of find do not have -mmin
+_have_find_mmin=1
+
+function olderThanMinutes() {
+    local matches
+    local find_exit_code
+
+    if [[ -z "$_find_command" ]]; then
+        if command -v gfind > /dev/null; then
+            _find_command=gfind
+        else
+            _find_command=find
+        fi
+    fi
+
+    if [[ "$_have_find_mmin" = 1 ]]; then
+        matches=`"$_find_command" "$1" -mmin +"$2" 2> /dev/null`
+        find_exit_code="$?"
+        if [[ -n "$matches" ]]; then
+            return 0
+        else
+            if [[ "$find_exit_code" != 0 ]]; then
+                _have_find_mmin=0
+            else
+                return 1
+            fi
+        fi
+    fi
+
+    # try perl, solaris ships with perl
+    if command -v perl > /dev/null; then
+        perl -e '((time - (stat("'"$1"'"))[9]) / 60) > '"$2"' && exit(0) || exit(1)'
+        return "$?"
+    else
+        echo >&2
+        echo "WARNING: neither a find that supports -mmin (such as GNU find) or perl is available, disabling remote status checking. Install GNU find as gfind or perl to enable this feature, or set GIT_PROMPT_FETCH_REMOTE_STATUS=0 to disable this warning." >&2
+        echo >&2
+        GIT_PROMPT_FETCH_REMOTE_STATUS=0
+        return 1
+    fi
+}
+
 function checkUpstream() {
   local GIT_PROMPT_FETCH_TIMEOUT
   git_prompt_config
 
   local FETCH_HEAD="$repo/.git/FETCH_HEAD"
   # Fech repo if local is stale for more than $GIT_FETCH_TIMEOUT minutes
-  if [[ ! -e "$FETCH_HEAD"  ||  -e `find "$FETCH_HEAD" -mmin +$GIT_PROMPT_FETCH_TIMEOUT` ]]
+  if [[ ! -e "$FETCH_HEAD" ]] || olderThanMinutes "$FETCH_HEAD" "$GIT_PROMPT_FETCH_TIMEOUT"
   then
     if [[ -n $(git remote show) ]]; then
       (
diff --git a/themes/Crunch.bgptheme b/themes/Crunch.bgptheme
index 1841e19..78b99a5 100644
--- a/themes/Crunch.bgptheme
+++ b/themes/Crunch.bgptheme
@@ -5,7 +5,7 @@ override_git_prompt_colors() {
   if [ -e ~/.rvm/bin/rvm-prompt ]; then
     RUBY_PROMPT='{$(~/.rvm/bin/rvm-prompt i v)}'
   else
-    if which rbenv &> /dev/null; then
+    if command -v rbenv > /dev/null; then
       RUBY_PROMPT='{$(rbenv version | sed -e "s/ (set.*$//")}'
     fi
   fi
@@ -31,4 +31,4 @@ GIT_PROMPT_START_USER="_LAST_COMMAND_INDICATOR_${White}{${Yellow}${Time12a}${Whi
   GIT_PROMPT_SYMBOLS_NO_REMOTE_TRACKING="✭"
 }
 
-reload_git_prompt_colors "Crunch"
\ No newline at end of file
+reload_git_prompt_colors "Crunch"
diff --git a/themes/Solarized_Extravagant.bgptheme b/themes/Solarized_Extravagant.bgptheme
index e5aef39..f93c362 100644
--- a/themes/Solarized_Extravagant.bgptheme
+++ b/themes/Solarized_Extravagant.bgptheme
@@ -7,7 +7,7 @@ override_git_prompt_colors() {
   if [ -e ~/.rvm/bin/rvm-prompt ]; then
     RUBY_PROMPT='{$(~/.rvm/bin/rvm-prompt i v)}'
   else
-    if which rbenv &> /dev/null; then
+    if command -v rbenv > /dev/null; then
       RUBY_PROMPT='{$(rbenv version | sed -e "s/ (set.*$//")}'
     fi
   fi
@@ -38,4 +38,4 @@ GIT_PROMPT_START_USER="_LAST_COMMAND_INDICATOR_ ${BoldBlueFg}${Time12a} ${Green}
   GIT_PROMPT_SYMBOLS_NO_REMOTE_TRACKING="✭"
 }
 
-reload_git_prompt_colors "Solarized Extravagant"
\ No newline at end of file
+reload_git_prompt_colors "Solarized Extravagant"