diff --git a/lib/tokenizer/tokenize.js b/lib/tokenizer/tokenize.js
index 8ad55d592..2d34e4d6f 100644
--- a/lib/tokenizer/tokenize.js
+++ b/lib/tokenizer/tokenize.js
@@ -120,6 +120,7 @@ function intoTokens(source, externalContext, internalContext, isNested) {
     isCommentStart = !wasCommentEnd && level != Level.COMMENT && !isQuoted && character == Marker.ASTERISK && source[position.index - 1] == Marker.FORWARD_SLASH;
     isCommentEndMarker = !wasCommentStart && !isQuoted && character == Marker.FORWARD_SLASH && source[position.index - 1] == Marker.ASTERISK;
     isCommentEnd = level == Level.COMMENT && isCommentEndMarker;
+    roundBracketLevel = Math.max(roundBracketLevel, 0);
 
     metadata = buffer.length === 0 ?
       [position.line, position.column, position.source] :
diff --git a/test/fixtures/issue-1001-min.css b/test/fixtures/issue-1001-min.css
new file mode 100644
index 000000000..a412a4f27
--- /dev/null
+++ b/test/fixtures/issue-1001-min.css
@@ -0,0 +1,2 @@
+.a{background-image:url(test/fixtures/bg-buttonh.png)}
+.e{background:url(/carte-bienvenue/bg2.jpg)}
diff --git a/test/fixtures/issue-1001.css b/test/fixtures/issue-1001.css
new file mode 100644
index 000000000..886591729
--- /dev/null
+++ b/test/fixtures/issue-1001.css
@@ -0,0 +1,4 @@
+.a{background-image:url('bg-buttonh.png'); }
+'/imagerie/booking/common/bg-buttonh.png');}
+.c{background:url(/carte-bienvenue/bg.jpg)}
+.e{background:url(/carte-bienvenue/bg2.jpg)}