diff --git a/docs/reference/gtk/css-properties.xml b/docs/reference/gtk/css-properties.xml
index e71f49e7a9..e992f1135b 100644
--- a/docs/reference/gtk/css-properties.xml
+++ b/docs/reference/gtk/css-properties.xml
@@ -444,8 +444,8 @@ We use <literallayout> for syntax productions, and each line is put in a <code>
               <entry></entry>
             </row>
             <row>
-              <entry>‑gtk‑icon‑effect</entry>
-              <entry><code>none | highlight | dim</code></entry>
+              <entry>‑gtk‑icon‑filter</entry>
+              <entry><code>none | 〈filter〉</code></entry>
               <entry><code>none</code></entry>
               <entry>✓</entry>
               <entry></entry>
@@ -466,6 +466,14 @@ We use <literallayout> for syntax productions, and each line is put in a <code>
 <code>                rotateX( 〈angle〉 ) | rotateY( 〈angle〉 ) | rotateZ( 〈angle〉 ) |</code>
 <code>                skew( 〈angle〉 [ , 〈angle〉 ]? ) | skewX( 〈angle〉 ) |  skewY( 〈angle〉 )</code>
 <code>〈color palette〉 = default | 〈name〉 〈color〉 [ , 〈name〉 〈color〉 ]*</code>
+<code>〈filter〉 = brightness( 〈number〉 ) |</code>
+<code>             contrast( 〈number〉 ) |</code>
+<code>             grayscale( 〈number〉 ) |</code>
+<code>             hue-rotate( 〈number〉 ) |</code>
+<code>             invert( 〈number〉 ) |</code>
+<code>             opacity( 〈number〉 ) |</code>
+<code>             saturate( 〈number〉 ) |</code>
+<code>             sepia( 〈number〉 )</code>
 </literallayout>
 
       <para>