diff --git a/dev-qt/qtquick3d/files/qtquick3d-6.11.2-stdlib.patch b/dev-qt/qtquick3d/files/qtquick3d-6.11.2-stdlib.patch
new file mode 100644
index 0000000000000..37933ab4c6dcf
--- /dev/null
+++ b/dev-qt/qtquick3d/files/qtquick3d-6.11.2-stdlib.patch
@@ -0,0 +1,8 @@
+xatlas.cpp:166:32: error: use of undeclared identifier 'realloc'
+(happened on llvm-musl with libcxx-23, but haven't narrowed down the cause)
+--- a/src/3rdparty/xatlas/xatlas.cpp
++++ b/src/3rdparty/xatlas/xatlas.cpp
+@@ -52,2 +52,3 @@
+ #include <stdint.h>
++#include <stdlib.h>
+ #include <stdio.h>
diff --git a/dev-qt/qtquick3d/qtquick3d-6.11.2.ebuild b/dev-qt/qtquick3d/qtquick3d-6.11.2.ebuild
index 807e67c739991..5a4d0d30fbb69 100644
--- a/dev-qt/qtquick3d/qtquick3d-6.11.2.ebuild
+++ b/dev-qt/qtquick3d/qtquick3d-6.11.2.ebuild
@@ -42,6 +42,7 @@ CMAKE_SKIP_TESTS=(
 PATCHES=(
 	"${FILESDIR}"/${PN}-6.6.2-gcc14.patch
 	"${FILESDIR}"/${PN}-6.6.2-x32abi.patch
+	"${FILESDIR}"/${PN}-6.11.2-stdlib.patch
 )
 
 src_configure() {
diff --git a/dev-qt/qtquick3d/qtquick3d-6.11.9999.ebuild b/dev-qt/qtquick3d/qtquick3d-6.11.9999.ebuild
index 807e67c739991..5a4d0d30fbb69 100644
--- a/dev-qt/qtquick3d/qtquick3d-6.11.9999.ebuild
+++ b/dev-qt/qtquick3d/qtquick3d-6.11.9999.ebuild
@@ -42,6 +42,7 @@ CMAKE_SKIP_TESTS=(
 PATCHES=(
 	"${FILESDIR}"/${PN}-6.6.2-gcc14.patch
 	"${FILESDIR}"/${PN}-6.6.2-x32abi.patch
+	"${FILESDIR}"/${PN}-6.11.2-stdlib.patch
 )
 
 src_configure() {
diff --git a/dev-qt/qtquick3d/qtquick3d-6.12.9999.ebuild b/dev-qt/qtquick3d/qtquick3d-6.12.9999.ebuild
index 807e67c739991..5a4d0d30fbb69 100644
--- a/dev-qt/qtquick3d/qtquick3d-6.12.9999.ebuild
+++ b/dev-qt/qtquick3d/qtquick3d-6.12.9999.ebuild
@@ -42,6 +42,7 @@ CMAKE_SKIP_TESTS=(
 PATCHES=(
 	"${FILESDIR}"/${PN}-6.6.2-gcc14.patch
 	"${FILESDIR}"/${PN}-6.6.2-x32abi.patch
+	"${FILESDIR}"/${PN}-6.11.2-stdlib.patch
 )
 
 src_configure() {
diff --git a/dev-qt/qtquick3d/qtquick3d-6.9999.ebuild b/dev-qt/qtquick3d/qtquick3d-6.9999.ebuild
index 807e67c739991..5a4d0d30fbb69 100644
--- a/dev-qt/qtquick3d/qtquick3d-6.9999.ebuild
+++ b/dev-qt/qtquick3d/qtquick3d-6.9999.ebuild
@@ -42,6 +42,7 @@ CMAKE_SKIP_TESTS=(
 PATCHES=(
 	"${FILESDIR}"/${PN}-6.6.2-gcc14.patch
 	"${FILESDIR}"/${PN}-6.6.2-x32abi.patch
+	"${FILESDIR}"/${PN}-6.11.2-stdlib.patch
 )
 
 src_configure() {