diff --git a/exec.c b/exec.c
index 59debc9..2646912 100644
--- a/exec.c
+++ b/exec.c
@@ -1150,6 +1150,11 @@
         }
         if (!new_block->host) {
             new_block->host = phys_mem_alloc(size);
+            if (!new_block->host) {
+                fprintf(stderr, "Cannot set up guest memory '%s': %s\n",
+                        new_block->mr->name, strerror(errno));
+                exit(1);
+            }
             memory_try_enable_merging(new_block->host, size);
         }
     }