diff --git a/inc/winfsp/fsctl.h b/inc/winfsp/fsctl.h
index 8ba9b2d8..4bd774b5 100644
--- a/inc/winfsp/fsctl.h
+++ b/inc/winfsp/fsctl.h
@@ -41,9 +41,10 @@ extern const __declspec(selectany) GUID FspFsvrtDeviceClassGuid =
 
 #define FSP_FSCTL_VOLUME_NAME_SIZEMAX   128
 
-#define FSP_FSCTL_TRANSACT_REQ_BUFFER_SIZEMIN 16384 /* checked by driver! */
 #define FSP_FSCTL_TRANSACT_REQ_SIZEMAX  (4096 - 64) /* 64: size for internal request header */
 #define FSP_FSCTL_TRANSACT_RSP_SIZEMAX  (4096 - 64) /* symmetry! */
+#define FSP_FSCTL_TRANSACT_BATCH_BUFFER_SIZEMIN 16384
+#define FSP_FSCTL_TRANSACT_BUFFER_SIZEMIN       FSP_FSCTL_TRANSACT_REQ_SIZEMAX
 
 /* volume/file metadata */
 typedef struct
diff --git a/src/dll/loop.c b/src/dll/loop.c
index 0ba42508..e7b21923 100644
--- a/src/dll/loop.c
+++ b/src/dll/loop.c
@@ -70,13 +70,13 @@ FSP_API NTSTATUS FspFileSystemLoop(FSP_FILE_SYSTEM *FileSystem)
     SIZE_T RequestBufSize;
     FSP_FSCTL_TRANSACT_REQ *Request, *NextRequest;
 
-    RequestBuf = MemAlloc(FSP_FSCTL_TRANSACT_REQ_SIZEMAX);
+    RequestBuf = MemAlloc(FSP_FSCTL_TRANSACT_BUFFER_SIZEMIN);
     if (0 == RequestBuf)
         return STATUS_INSUFFICIENT_RESOURCES;
 
     for (;;)
     {
-        RequestBufSize = FSP_FSCTL_TRANSACT_REQ_SIZEMAX;
+        RequestBufSize = FSP_FSCTL_TRANSACT_BUFFER_SIZEMIN;
         Result = FspFsctlTransact(FileSystem->VolumeHandle, 0, 0, RequestBuf, &RequestBufSize, FALSE);
         if (!NT_SUCCESS(Result))
             goto exit;
diff --git a/src/sys/volume.c b/src/sys/volume.c
index 29a5e324..a3ab2416 100644
--- a/src/sys/volume.c
+++ b/src/sys/volume.c
@@ -513,9 +513,9 @@ NTSTATUS FspVolumeTransact(
         return STATUS_INVALID_PARAMETER;
     if (0 != OutputBufferLength &&
         ((FSP_FSCTL_TRANSACT == ControlCode &&
-            FSP_FSCTL_TRANSACT_REQ_SIZEMAX > OutputBufferLength) ||
+            FSP_FSCTL_TRANSACT_BUFFER_SIZEMIN > OutputBufferLength) ||
         (FSP_FSCTL_TRANSACT_BATCH == ControlCode &&
-            FSP_FSCTL_TRANSACT_REQ_BUFFER_SIZEMIN > OutputBufferLength)))
+            FSP_FSCTL_TRANSACT_BATCH_BUFFER_SIZEMIN > OutputBufferLength)))
         return STATUS_BUFFER_TOO_SMALL;
 
     if (!FspDeviceReference(FsvolDeviceObject))
diff --git a/tst/winfsp-tests/mount-test.c b/tst/winfsp-tests/mount-test.c
index 6637e62c..2457e05e 100644
--- a/tst/winfsp-tests/mount-test.c
+++ b/tst/winfsp-tests/mount-test.c
@@ -173,7 +173,7 @@ void mount_volume_transact_dotest(PWSTR DeviceName, PWSTR Prefix)
 
     Sleep(1000); /* give some time to the thread to execute */
 
-    FSP_FSCTL_DECLSPEC_ALIGN UINT8 RequestBuf[FSP_FSCTL_TRANSACT_REQ_BUFFER_SIZEMIN];
+    FSP_FSCTL_DECLSPEC_ALIGN UINT8 RequestBuf[FSP_FSCTL_TRANSACT_BATCH_BUFFER_SIZEMIN];
     FSP_FSCTL_DECLSPEC_ALIGN UINT8 ResponseBuf[FSP_FSCTL_TRANSACT_RSP_SIZEMAX];
     UINT8 *RequestBufEnd;
     UINT8 *ResponseBufEnd = ResponseBuf + sizeof ResponseBuf;
diff --git a/tst/winfsp-tests/timeout-test.c b/tst/winfsp-tests/timeout-test.c
index cf998e30..cb4c12ba 100644
--- a/tst/winfsp-tests/timeout-test.c
+++ b/tst/winfsp-tests/timeout-test.c
@@ -168,7 +168,7 @@ void timeout_transact_dotest(PWSTR DeviceName, PWSTR Prefix)
     ASSERT(INVALID_HANDLE_VALUE != VolumeHandle);
 
 
-    FSP_FSCTL_DECLSPEC_ALIGN UINT8 RequestBuf[FSP_FSCTL_TRANSACT_REQ_BUFFER_SIZEMIN];
+    FSP_FSCTL_DECLSPEC_ALIGN UINT8 RequestBuf[FSP_FSCTL_TRANSACT_BATCH_BUFFER_SIZEMIN];
     FSP_FSCTL_DECLSPEC_ALIGN UINT8 ResponseBuf[FSP_FSCTL_TRANSACT_RSP_SIZEMAX];
     UINT8 *RequestBufEnd;
     UINT8 *ResponseBufEnd = ResponseBuf + sizeof ResponseBuf;