diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3afd90e17..9365efb33 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,6 +29,6 @@ set(CMAKE_CXX_EXTENSIONS OFF)
 
 # Find libvips (required)
 find_package(PkgConfig)
-pkg_check_modules(VIPS vips>=8.15 REQUIRED)
+pkg_check_modules(VIPS vips>=8.16 REQUIRED)
 
 add_subdirectory(src)
diff --git a/build.sh b/build.sh
index 4f8cb3272..4420dcd7b 100755
--- a/build.sh
+++ b/build.sh
@@ -195,7 +195,7 @@ VERSION_TIFF=4.7.0          # https://gitlab.com/libtiff/libtiff
 VERSION_RESVG=0.44.0        # https://github.com/RazrFalcon/resvg
 VERSION_AOM=3.10.0          # https://aomedia.googlesource.com/aom
 VERSION_HEIF=1.18.2         # https://github.com/strukturag/libheif
-VERSION_VIPS=8.16.0-rc1     # https://github.com/libvips/libvips
+VERSION_VIPS=8.16.0-rc2     # https://github.com/libvips/libvips
 
 VERSION_EMSCRIPTEN="$(emcc -dumpversion)"
 
diff --git a/test/unit/node-helper.js b/test/unit/node-helper.js
index a092a7f79..75d34f185 100644
--- a/test/unit/node-helper.js
+++ b/test/unit/node-helper.js
@@ -22,6 +22,7 @@ export async function mochaGlobalSetup () {
       // Handy for debugging
       // module.ENV.VIPS_INFO = 1;
       // module.ENV.VIPS_LEAK = 1;
+      // module.ENV.VIPS_CONCURRENCY = 1;
 
       // Hide warning messages
       module.ENV.VIPS_WARNING = 0;
diff --git a/test/unit/test_foreign.js b/test/unit/test_foreign.js
index 8f667cda3..c04c2dd51 100644
--- a/test/unit/test_foreign.js
+++ b/test/unit/test_foreign.js
@@ -1047,8 +1047,8 @@ describe('foreign', () => {
       }
 
       // Chroma subsampling should produce smaller file size for same Q
-      const b1 = mono.heifsaveBuffer({ compression: 'av1', subsample_mode: 'on' });
-      const b2 = mono.heifsaveBuffer({ compression: 'av1', subsample_mode: 'off' });
+      const b1 = colour.heifsaveBuffer({ compression: 'av1', subsample_mode: 'on' });
+      const b2 = colour.heifsaveBuffer({ compression: 'av1', subsample_mode: 'off' });
       expect(b2.byteLength).to.be.above(b1.byteLength);
     });