diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index 0278902ee79d..f7e22f4ff9b0 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -209,6 +209,9 @@ void *qemu_try_memalign(size_t alignment, size_t size)
         g_assert(is_power_of_2(alignment));
     }
 
+    if (size == 0) {
+        size++;
+    }
 #if defined(CONFIG_POSIX_MEMALIGN)
     int ret;
     ret = posix_memalign(&ptr, alignment, size);
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 058574146951..8c28d70904de 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -48,12 +48,14 @@ void *qemu_try_memalign(size_t alignment, size_t size)
 {
     void *ptr;
 
-    g_assert(size != 0);
     if (alignment < sizeof(void *)) {
         alignment = sizeof(void *);
     } else {
         g_assert(is_power_of_2(alignment));
     }
+    if (size == 0) {
+        size++;
+    }
     ptr = _aligned_malloc(size, alignment);
     trace_qemu_memalign(alignment, size, ptr);
     return ptr;