diff --git a/lib/Minify/CSS.php b/lib/Minify/CSS.php
index aa9783d..80c48c5 100644
--- a/lib/Minify/CSS.php
+++ b/lib/Minify/CSS.php
@@ -190,7 +190,7 @@ class Minify_CSS {
             self::$_inHack = true;
             return '/*\\*/';
         }
-        if ($m[0] === '/') {
+        if ($m !== '' && $m[0] === '/') {
             self::$_inHack = true;
             return '/*/*/';
         }
diff --git a/web/test/_test_files/css/hacks.css b/web/test/_test_files/css/hacks.css
index 469572a..4888ba3 100644
--- a/web/test/_test_files/css/hacks.css
+++ b/web/test/_test_files/css/hacks.css
@@ -41,4 +41,12 @@ div {
 div {
   filter:chroma(color=#aabbcc);
   filter:mask(color=#000000) shadow(color=#9BAD71, direction=135) chroma(color=#000000);
+}
+
+@media screen {
+    /* for IE 5.x-6, hidden from IE 5 Mac */ /*\*/
+    * html div#page {
+        height: 1%;
+    }
+    /**/ /* end hidden from IE 5 Mac */
 }
\ No newline at end of file
diff --git a/web/test/_test_files/css/hacks.min.css b/web/test/_test_files/css/hacks.min.css
index 18fe079..569a8f6 100644
--- a/web/test/_test_files/css/hacks.min.css
+++ b/web/test/_test_files/css/hacks.min.css
@@ -1 +1 @@
-/*\*/a{}.foo{color:red}/**//*\*//*/@import "ie5mac.css";/**//*/*/.foo{display:block}/**//*/*//*/.foo{display:crazy}/**/div{width:140px;width/**/:/**/100px;width:/**/100px}html>/**/body{}div{width:400px;voice-family: "\"}\"";voice-family:inherit;width:300px}div{filter:chroma(color=#aabbcc);filter:mask(color=#000000) shadow(color=#9BAD71, direction=135) chroma(color=#000000)}
\ No newline at end of file
+/*\*/a{}.foo{color:red}/**//*\*//*/@import "ie5mac.css";/**//*/*/.foo{display:block}/**//*/*//*/.foo{display:crazy}/**/div{width:140px;width/**/:/**/100px;width:/**/100px}html>/**/body{}div{width:400px;voice-family: "\"}\"";voice-family:inherit;width:300px}div{filter:chroma(color=#aabbcc);filter:mask(color=#000000) shadow(color=#9BAD71, direction=135) chroma(color=#000000)}@media screen{/*\*/* html div#page{height:1%}/**/}
\ No newline at end of file