diff --git a/data/custom.xml b/data/custom.xml
index 42b5134..6659a9f 100644
--- a/data/custom.xml
+++ b/data/custom.xml
@@ -83,6 +83,7 @@
           <match value="webm" type="string" offset="4:4096">
             <match value="V_VP8" type="string" offset="4:4096" />
             <match value="V_VP9" type="string" offset="4:4096" />
+            <match value="V_AV1" type="string" offset="4:4096" />
           </match>
         </match>
       </match>
diff --git a/lib/marcel/tables.rb b/lib/marcel/tables.rb
index 52e0290..6ed62b6 100644
--- a/lib/marcel/tables.rb
+++ b/lib/marcel/tables.rb
@@ -2407,7 +2407,7 @@ module Marcel
     ['audio/mp4', [[4, b['ftypM4A ']], [4, b['ftypM4B ']], [4, b['ftypF4A ']], [4, b['ftypF4B ']]]],
     ['video/quicktime', [[4, b["moov\000"]], [4, b["mdat\000"]], [4, b["free\000"]], [4, b["skip\000"]], [4, b["pnot\000"]], [4, b['ftyp']], [0, b["\000\000\000\bwide"]]]],
     ['video/mpeg', [[0, b["\000\000\001\263"]], [0, b["\000\000\001\272"]]]],
-    ['video/webm', [[0, b["\032E\337\243"], [[4..4096, b["B\202"], [[4..4096, b['webm'], [[4..4096, b['V_VP8']], [4..4096, b['V_VP9']]]]]]]]]],
+    ['video/webm', [[0, b["\032E\337\243"], [[4..4096, b["B\202"], [[4..4096, b['webm'], [[4..4096, b['V_VP8']], [4..4096, b['V_VP9']], [4..4096, b['V_AV1']]]]]]]]]],
     ['video/x-matroska', [[0, b["\032E\337\243\223B\202\210matroska"]]]],
     ['video/x-flv', [[0, b['FLV']]]],
     ['audio/mpeg', [[0, b["\377\362"]], [0, b["\377\363"]], [0, b["\377\364"]], [0, b["\377\365"]], [0, b["\377\366"]], [0, b["\377\367"]], [0, b["\377\372"]], [0, b["\377\373"]], [0, b["\377\374"]], [0, b["\377\375"]], [0, b["\377\377"]], [0, b['ID3']]]],
diff --git a/test/fixtures/magic/video/webm/webm.webm b/test/fixtures/magic/video/webm/webm.webm
new file mode 100644
index 0000000..22863ea
Binary files /dev/null and b/test/fixtures/magic/video/webm/webm.webm differ