diff --git a/mmap.go b/mmap.go
index 6708492..7d6abd0 100644
--- a/mmap.go
+++ b/mmap.go
@@ -15,6 +15,7 @@ import (
 var (
 	uint32Size = uint32(unsafe.Sizeof(uint32(0)))
 	sqeSize    = uint32(unsafe.Sizeof(iouring_syscall.SubmissionQueueEntry{}))
+	cqeSize    = uint32(unsafe.Sizeof(iouring_syscall.CompletionQueueEvent{}))
 )
 
 func mmapIOURing(iour *IOURing) (err error) {
@@ -26,7 +27,17 @@ func mmapIOURing(iour *IOURing) (err error) {
 	iour.sq = new(SubmissionQueue)
 	iour.cq = new(CompletionQueue)
 
-	if err = mmapSQ(iour); err != nil {
+	iour.sq.size = iour.params.SQOffset.Array + iour.params.SQEntries*uint32Size
+	iour.cq.size = iour.params.CQOffset.Cqes + iour.params.CQEntries*cqeSize
+	if (iour.params.Features & iouring_syscall.IORING_FEAT_SINGLE_MMAP) != 0 {
+		if iour.cq.size > iour.sq.size {
+			iour.sq.size = iour.cq.size
+		} else {
+			iour.cq.size = iour.sq.size
+		}
+	}
+
+	if err = mmapSQ(iour.fd, iour.params, iour.sq); err != nil {
 		return err
 	}
 
@@ -34,22 +45,18 @@ func mmapIOURing(iour *IOURing) (err error) {
 		iour.cq.ptr = iour.sq.ptr
 	}
 
-	if err = mmapCQ(iour); err != nil {
+	if err = mmapCQ(iour.fd, iour.params, iour.cq); err != nil {
 		return err
 	}
 
-	if err = mmapSQEs(iour); err != nil {
+	if err = mmapSQEs(iour.fd, iour.params, iour.sq); err != nil {
 		return err
 	}
 	return nil
 }
 
-func mmapSQ(iour *IOURing) (err error) {
-	sq := iour.sq
-	params := iour.params
-
-	sq.size = params.SQOffset.Array + params.SQEntries*uint32Size
-	sq.ptr, err = mmap(iour.fd, sq.size, iouring_syscall.IORING_OFF_SQ_RING)
+func mmapSQ(fd int, params *iouring_syscall.IOURingParams, sq *SubmissionQueue) (err error) {
+	sq.ptr, err = mmap(fd, sq.size, iouring_syscall.IORING_OFF_SQ_RING)
 	if err != nil {
 		return fmt.Errorf("mmap sq ring: %w", err)
 	}
@@ -66,17 +73,12 @@ func mmapSQ(iour *IOURing) (err error) {
 		Len:  int(params.SQEntries),
 		Cap:  int(params.SQEntries),
 	}))
-
 	return nil
 }
 
-func mmapCQ(iour *IOURing) (err error) {
-	params := iour.params
-	cq := iour.cq
-
-	cq.size = params.CQOffset.Cqes + params.CQEntries*uint32Size
+func mmapCQ(fd int, params *iouring_syscall.IOURingParams, cq *CompletionQueue) (err error) {
 	if cq.ptr == 0 {
-		cq.ptr, err = mmap(iour.fd, cq.size, iouring_syscall.IORING_OFF_CQ_RING)
+		cq.ptr, err = mmap(fd, cq.size, iouring_syscall.IORING_OFF_CQ_RING)
 		if err != nil {
 			return fmt.Errorf("mmap cq ring: %w", err)
 		}
@@ -94,25 +96,21 @@ func mmapCQ(iour *IOURing) (err error) {
 			Len:  int(params.CQEntries),
 			Cap:  int(params.CQEntries),
 		}))
-
 	return nil
 }
 
-func mmapSQEs(iour *IOURing) error {
-	params := iour.params
-
-	ptr, err := mmap(iour.fd, params.SQEntries*sqeSize, iouring_syscall.IORING_OFF_SQES)
+func mmapSQEs(fd int, params *iouring_syscall.IOURingParams, sq *SubmissionQueue) (err error) {
+	ptr, err := mmap(fd, params.SQEntries*sqeSize, iouring_syscall.IORING_OFF_SQES)
 	if err != nil {
 		return fmt.Errorf("mmap sqe array: %w", err)
 	}
 
-	iour.sq.sqes = *(*[]iouring_syscall.SubmissionQueueEntry)(
+	sq.sqes = *(*[]iouring_syscall.SubmissionQueueEntry)(
 		unsafe.Pointer(&reflect.SliceHeader{
 			Data: ptr,
 			Len:  int(params.SQEntries),
 			Cap:  int(params.SQEntries),
 		}))
-
 	return nil
 }
 
@@ -141,7 +139,6 @@ func munmapIOURing(iour *IOURing) error {
 		}
 		iour.cq = nil
 	}
-
 	return nil
 }