diff --git a/.github/matrix.json b/.github/matrix.json
index a2ee03443..8be64b25e 100644
--- a/.github/matrix.json
+++ b/.github/matrix.json
@@ -1,9 +1,9 @@
 {
     "config": [
         {
-            "name": "Linux GCC 10",
+            "name": "Linux GCC 11",
             "compiler": "gcc",
-            "version": "10",
+            "version": "11",
             "os": "ubuntu-22.04"
         },
         {
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 6a3d348a4..a485da8b1 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -87,6 +87,12 @@ add_executable( stlab.test.cow
   cow_test.cpp
   main.cpp )
 
+# Disable warning on GCC 11 and above for cow_test.cpp. See
+# github.com/stlab/libraries/issues/438 for details.
+if( CMAKE_CXX_COMPILER_ID STREQUAL "GNU" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL "11" )
+  set_source_files_properties( cow_test.cpp PROPERTIES COMPILE_FLAGS -Wno-free-nonheap-object )
+endif()
+
 target_compile_definitions(stlab.test.cow PRIVATE STLAB_UNIT_TEST)
 
 target_link_libraries( stlab.test.cow PUBLIC stlab::testing )