diff --git a/packages/svelte2tsx/src/htmlxtojsx_v2/nodes/Attribute.ts b/packages/svelte2tsx/src/htmlxtojsx_v2/nodes/Attribute.ts
index 12f3396ee..0ef4095cc 100644
--- a/packages/svelte2tsx/src/htmlxtojsx_v2/nodes/Attribute.ts
+++ b/packages/svelte2tsx/src/htmlxtojsx_v2/nodes/Attribute.ts
@@ -94,7 +94,7 @@ export function handleAttribute(
                   element.addAttribute(name, value);
               }
             : (name: TransformationArray, value?: TransformationArray) => {
-                  if (attr.name.startsWith('--') && attr.value !== true) {
+                  if (attr.name.startsWith('--')) {
                       // CSS custom properties are not part of the props
                       // definition, so wrap them to not get "--xx is invalid prop" errors
                       name.unshift('...__sveltets_2_cssProp({');
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/expectedv2.js b/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/expectedv2.js
index 1968d107d..481e683cc 100644
--- a/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/expectedv2.js
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/expectedv2.js
@@ -1 +1 @@
-  { const $$_tnenopmoC0C = __sveltets_2_ensureComponent(Component); new $$_tnenopmoC0C({ target: __sveltets_2_any(), props: {          ...__sveltets_2_cssProp({"--custom-css-property1":'hi'}),...__sveltets_2_cssProp({"--custom-css-property2":`hi`}),"betweenprop":true,...__sveltets_2_cssProp({"--custom-css-property3":`hi${jo}hi`}),...__sveltets_2_cssProp({"--custom-css-property4":`hi${jo}hi`}),...__sveltets_2_cssProp({"--custom-css-property5":`hi${jo}hi`}),}});}
\ No newline at end of file
+  { const $$_tnenopmoC0C = __sveltets_2_ensureComponent(Component); new $$_tnenopmoC0C({ target: __sveltets_2_any(), props: {           ...__sveltets_2_cssProp({"--custom-css-property1":'hi'}),...__sveltets_2_cssProp({"--custom-css-property2":`hi`}),"betweenprop":true,...__sveltets_2_cssProp({"--custom-css-property3":`hi${jo}hi`}),...__sveltets_2_cssProp({"--custom-css-property4":`hi${jo}hi`}),...__sveltets_2_cssProp({"--custom-css-property5":`hi${jo}hi`}),...__sveltets_2_cssProp({"--custom-css-property6":true}),}});}
\ No newline at end of file
diff --git a/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/input.svelte b/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/input.svelte
index 22f7f271b..316a0d999 100644
--- a/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/input.svelte
+++ b/packages/svelte2tsx/test/htmlx2jsx/samples/custom-css-properties/input.svelte
@@ -4,4 +4,5 @@
   betweenprop
   --custom-css-property3="hi{jo}hi"
   --custom-css-property4='hi{jo}hi'
-  --custom-css-property5=hi{jo}hi />
+  --custom-css-property5=hi{jo}hi
+  --custom-css-property6 />