https://github.com/ImageMagick/ImageMagick/issues/792
diff --git a/MagickCore/opencl.c b/MagickCore/opencl.c
index bf27dea..78e81fb 100644
--- a/MagickCore/opencl.c
+++ b/MagickCore/opencl.c
@@ -1163,7 +1163,7 @@
 
   testEnv=AcquireMagickCLEnv();
   testEnv->library=openCL_library;
-  testEnv->devices=(MagickCLDevice *) AcquireMagickMemory(
+  testEnv->devices=(MagickCLDevice *) AcquireCriticalMemory(
     sizeof(MagickCLDevice));
   testEnv->number_devices=1;
   testEnv->benchmark_thread_id=GetMagickThreadId();