diff --git a/Libraries/LibWeb/CSS/Properties.json b/Libraries/LibWeb/CSS/Properties.json
index feaabf4b7c6..58257369d3b 100644
--- a/Libraries/LibWeb/CSS/Properties.json
+++ b/Libraries/LibWeb/CSS/Properties.json
@@ -2848,7 +2848,7 @@
"inherited": false,
"initial": "0s",
"valid-types": [
- "time"
+ "time [0,∞]"
]
},
"transition-property": {
diff --git a/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-invalid.txt b/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-invalid.txt
new file mode 100644
index 00000000000..c5c34d61357
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/css/css-transitions/parsing/transition-duration-invalid.txt
@@ -0,0 +1,10 @@
+Harness status: OK
+
+Found 5 tests
+
+5 Pass
+Pass e.style['transition-duration'] = "infinite" should not set the property value
+Pass e.style['transition-duration'] = "-500ms" should not set the property value
+Pass e.style['transition-duration'] = "1s 2s" should not set the property value
+Pass e.style['transition-duration'] = "1s, initial" should not set the property value
+Pass e.style['transition-duration'] = "initial, 1s" should not set the property value
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-invalid.html b/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-invalid.html
new file mode 100644
index 00000000000..4fe9d98502a
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/css/css-transitions/parsing/transition-duration-invalid.html
@@ -0,0 +1,22 @@
+
+
+
+
+CSS Transitions: parsing transition-duration with invalid values
+
+
+
+
+
+
+
+
+
+