diff --git a/t/t4018/css-attribute-value-selector b/t/t4018/css-attribute-value-selector
new file mode 100644
index 0000000000..918256b20c
--- /dev/null
+++ b/t/t4018/css-attribute-value-selector
@@ -0,0 +1,4 @@
+[class*="RIGHT"] {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-block-level-@-statements b/t/t4018/css-block-level-@-statements
new file mode 100644
index 0000000000..d6755f2f3d
--- /dev/null
+++ b/t/t4018/css-block-level-@-statements
@@ -0,0 +1,10 @@
+@keyframes RIGHT {
+    from {
+        background : #000;
+        border : 10px ChangeMe #C6C6C6;
+    }
+    to {
+        background : #fff;
+        border : 10px solid #C6C6C6;
+    }
+}
diff --git a/t/t4018/css-class-selector b/t/t4018/css-class-selector
new file mode 100644
index 0000000000..f790a0062f
--- /dev/null
+++ b/t/t4018/css-class-selector
@@ -0,0 +1,4 @@
+.RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-id-selector b/t/t4018/css-id-selector
new file mode 100644
index 0000000000..17c5111052
--- /dev/null
+++ b/t/t4018/css-id-selector
@@ -0,0 +1,4 @@
+#RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/t/t4018/css-root-selector b/t/t4018/css-root-selector
new file mode 100644
index 0000000000..22b958e369
--- /dev/null
+++ b/t/t4018/css-root-selector
@@ -0,0 +1,4 @@
+:RIGHT {
+    background : #000;
+    border : 10px ChangeMe #C6C6C6;
+}
diff --git a/userdiff.c b/userdiff.c
index df85f0b8c5..9c63be9fb8 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -200,7 +200,7 @@ PATTERNS("csharp",
 	 "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
 IPATTERN("css",
 	 "![:;][[:space:]]*$\n"
-	 "^[_a-z0-9].*$",
+	 "^[:[@.#]?[_a-z0-9].*$",
 	 /* -- */
 	 /*
 	  * This regex comes from W3C CSS specs. Should theoretically also