diff --git a/dlls/netapi32/tests/access.c b/dlls/netapi32/tests/access.c
index 3cf6cb35ddb..0f0ac5417f1 100644
--- a/dlls/netapi32/tests/access.c
+++ b/dlls/netapi32/tests/access.c
@@ -494,10 +494,10 @@ START_TEST(access)
     pDavGetHTTPFromUNCPath = (void*)GetProcAddress(hnetapi32, "DavGetHTTPFromUNCPath");
     pDavGetUNCFromHTTPPath = (void*)GetProcAddress(hnetapi32, "DavGetUNCFromHTTPPath");
 
-    size = sizeof(user_name);
+    size = ARRAY_SIZE(user_name);
     ret = GetUserNameW(user_name, &size);
     ok(ret, "Failed to get user name, error %u.\n", GetLastError());
-    size = sizeof(computer_name);
+    size = ARRAY_SIZE(computer_name);
     ret = GetComputerNameW(computer_name, &size);
     ok(ret, "Failed to get computer name, error %u.\n", GetLastError());
 
diff --git a/dlls/netapi32/tests/wksta.c b/dlls/netapi32/tests/wksta.c
index 684905c4dcb..f53fcbbcce1 100644
--- a/dlls/netapi32/tests/wksta.c
+++ b/dlls/netapi32/tests/wksta.c
@@ -175,10 +175,10 @@ START_TEST(wksta)
 
     pNetpGetComputerName = (void *)GetProcAddress(GetModuleHandleA("netapi32.dll"), "NetpGetComputerName");
 
-    size = sizeof(user_name);
+    size = ARRAY_SIZE(user_name);
     ret = GetUserNameW(user_name, &size);
     ok(ret, "Failed to get user name, error %u.\n", GetLastError());
-    size = sizeof(computer_name);
+    size = ARRAY_SIZE(computer_name);
     ret = GetComputerNameW(computer_name, &size);
     ok(ret, "Failed to get computer name, error %u.\n", GetLastError());