diff --git a/installer.php b/installer.php
index 00c4e6b57300c3d6313a57d51214df0d3d321e44..1f592b287b4dacd488c9c03e9cb37e38130c2fd6 100755
--- a/installer.php
+++ b/installer.php
@@ -12,7 +12,7 @@ require("inc_functions.php");
 
 $gitAppmonitor="https://github.com/iml-it/appmonitor.git";
 $spcUrl="https://dl.static-php.dev/static-php-cli/spc-bin/nightly/spc-$myos-$myarchitecture";
-$doneBuild="__done_build-micro__".md5($php_version.$php_libs).".txt";
+$doneBuild="__done_build-micro__.txt";
 
 /*
 Filename                                          Last Modified            Size      Download Count
@@ -39,7 +39,7 @@ echo "
     - gets appmonitor sources
     - gets spc binary
     - spc downloads PHP and libs
-    - spc builds micro (1..2 min)
+    - spc builds micro (~2 min)
 
 
 ";
@@ -132,16 +132,25 @@ if (PHP_OS == "Linux") {
 _h1("Spc - prepare environment");
 _chdir("$selfdir/$dirBuild");
 
-if(!file_exists("$doneBuild")){
+$bDoBild=true;
+$sDoneData="PHP version $php_version\nExtensions: $php_libs";
+if(file_exists($doneBuild)){
+
+    $sDone=file_get_contents($doneBuild);
+    if (strstr($sDone, $sDoneData)>=0){
+        $bDoBild=false;
+    }
+}
+
+if ($bDoBild){    
     _exec("$SPC --no-interaction doctor");
     _exec("$SPC download --no-interaction --with-php=$php_version --for-extensions '$php_libs'");
 
     echo "💡 Hint: this can take 2 minutes ...\n";
     _exec("$SPC build --no-interaction --build-micro '$php_libs'");
-    touch("$doneBuild");
+    file_put_contents("$doneBuild", date("Y-m-d H:i:s") . "\n$sDoneData\n");
 } else {
     _skip("Micro already built - php $php_version - extensions '$php_libs'");
 }
 
-
 _h1("Done.");