diff --git a/.changeset/grumpy-clocks-jump.md b/.changeset/grumpy-clocks-jump.md
new file mode 100644
index 000000000..5f71d99c8
--- /dev/null
+++ b/.changeset/grumpy-clocks-jump.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/compiler': patch
+---
+
+Preserve namespaced attributes when using expressions
diff --git a/internal/printer/printer.go b/internal/printer/printer.go
index e71a73cf6..eeaaf0977 100644
--- a/internal/printer/printer.go
+++ b/internal/printer/printer.go
@@ -266,22 +266,25 @@ func (p *printer) printAttributesToObject(n *astro.Node) {
 		if a.Key == "set:text" || a.Key == "set:html" || a.Key == "is:raw" {
 			continue
 		}
+		if a.Namespace != "" {
+			a.Key = fmt.Sprintf(`%s:%s`, a.Namespace, a.Key)
+		}
 		lastAttributeSkipped = false
 		switch a.Type {
 		case astro.QuotedAttribute:
 			p.addSourceMapping(a.KeyLoc)
-			p.print(`"` + a.Key + `"`)
+			p.printf(`"%s"`, a.Key)
 			p.print(":")
 			p.addSourceMapping(a.ValLoc)
 			p.print(`"` + escapeDoubleQuote(a.Val) + `"`)
 		case astro.EmptyAttribute:
 			p.addSourceMapping(a.KeyLoc)
-			p.print(`"` + a.Key + `"`)
+			p.printf(`"%s"`, a.Key)
 			p.print(":")
 			p.print("true")
 		case astro.ExpressionAttribute:
 			p.addSourceMapping(a.KeyLoc)
-			p.print(`"` + a.Key + `"`)
+			p.printf(`"%s"`, a.Key)
 			p.print(":")
 			p.addSourceMapping(a.ValLoc)
 			if a.Val == "" {
@@ -305,7 +308,7 @@ func (p *printer) printAttributesToObject(n *astro.Node) {
 			p.print(`(` + strings.TrimSpace(a.Key) + `)`)
 		case astro.TemplateLiteralAttribute:
 			p.addSourceMapping(a.KeyLoc)
-			p.print(`"` + strings.TrimSpace(a.Key) + `"`)
+			p.printf(`"%s"`, strings.TrimSpace(a.Key))
 			p.print(":")
 			p.print("`" + strings.TrimSpace(a.Key) + "`")
 		}
@@ -323,8 +326,7 @@ func (p *printer) printAttribute(attr astro.Attribute, n *astro.Node) {
 	}
 
 	if attr.Namespace != "" {
-		p.print(attr.Namespace)
-		p.print(":")
+		attr.Key = fmt.Sprintf("%s:%s", attr.Namespace, attr.Key)
 	}
 
 	switch attr.Type {
diff --git a/internal/printer/printer_test.go b/internal/printer/printer_test.go
index 83f6847a8..059daaf29 100644
--- a/internal/printer/printer_test.go
+++ b/internal/printer/printer_test.go
@@ -1665,6 +1665,20 @@ import { Container, Col, Row } from 'react-bootstrap';
 				code: `${$$maybeRenderHead($$result)}<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><rect xlink:href="#id"></rect></svg>`,
 			},
 		},
+		{
+			name:   "Preserve namespaces in expressions",
+			source: `<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><rect xlink:href={` + BACKTICK + `#${iconId}` + BACKTICK + `}></svg>`,
+			want: want{
+				code: `${$$maybeRenderHead($$result)}<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><rect ${$$addAttribute(` + BACKTICK + `#${iconId}` + BACKTICK + `, "xlink:href")}></rect></svg>`,
+			},
+		},
+		{
+			name:   "Preserve namespaces for components",
+			source: `<Component some:thing="foobar">`,
+			want: want{
+				code: `${$$renderComponent($$result,'Component',Component,{"some:thing":"foobar"})}`,
+			},
+		},
 		{
 			name: "import.meta.env",
 			source: fmt.Sprintf(`---