diff --git a/sys/fs/fuse/fuse_vnops.c b/sys/fs/fuse/fuse_vnops.c
--- a/sys/fs/fuse/fuse_vnops.c
+++ b/sys/fs/fuse/fuse_vnops.c
@@ -625,7 +625,7 @@
 		return (EROFS);
 
 	if (fsess_not_impl(mp, FUSE_FALLOCATE))
-		return (EXTERROR(EINVAL, "This server does not implement "
+		return (EXTERROR(EOPNOTSUPP, "This server does not implement "
 		    "FUSE_FALLOCATE"));
 
 	io.uio_offset = *offset;
@@ -656,7 +656,7 @@
 
 	if (err == ENOSYS) {
 		fsess_set_notimpl(mp, FUSE_FALLOCATE);
-		err = EXTERROR(EINVAL, "This server does not implement "
+		err = EXTERROR(EOPNOTSUPP, "This server does not implement "
 		    "FUSE_ALLOCATE");
 	} else if (err == EOPNOTSUPP) {
 		/*
diff --git a/tests/sys/fs/fusefs/fallocate.cc b/tests/sys/fs/fusefs/fallocate.cc
--- a/tests/sys/fs/fusefs/fallocate.cc
+++ b/tests/sys/fs/fusefs/fallocate.cc
@@ -205,7 +205,7 @@
 	EXPECT_EQ(0, fspacectl(fd, SPACECTL_DEALLOC, &rqsr, 0, NULL));
 
 	/* Neither should posix_fallocate query the daemon */
-	EXPECT_EQ(EINVAL, posix_fallocate(fd, off1, len1));
+	EXPECT_EQ(EOPNOTSUPP, posix_fallocate(fd, off1, len1));
 
 	leak(fd);
 }
@@ -548,7 +548,7 @@
 
 /*
  * If the server returns ENOSYS, it indicates that the server does not support
- * FUSE_FALLOCATE.  This and future calls should return EINVAL.
+ * FUSE_FALLOCATE.  This and future calls should return EOPNOTSUPP.
  */
 TEST_F(PosixFallocate, enosys)
 {
@@ -570,10 +570,10 @@
 
 	fd = open(FULLPATH, O_RDWR);
 	ASSERT_LE(0, fd) << strerror(errno);
-	EXPECT_EQ(EINVAL, posix_fallocate(fd, off0, len0));
+	EXPECT_EQ(EOPNOTSUPP, posix_fallocate(fd, off0, len0));
 
 	/* Subsequent calls shouldn't query the daemon*/
-	EXPECT_EQ(EINVAL, posix_fallocate(fd, off0, len0));
+	EXPECT_EQ(EOPNOTSUPP, posix_fallocate(fd, off0, len0));
 
 	/* Neither should VOP_DEALLOCATE query the daemon */
 	EXPECT_EQ(0, fspacectl(fd, SPACECTL_DEALLOC, &rqsr, 0, NULL));
@@ -759,7 +759,7 @@
 }
 
 /* With older servers, no FUSE_FALLOCATE should be attempted */
-TEST_F(PosixFallocate_7_18, einval)
+TEST_F(PosixFallocate_7_18, eopnotsupp)
 {
 	const char FULLPATH[] = "mountpoint/some_file.txt";
 	const char RELPATH[] = "some_file.txt";
@@ -773,7 +773,7 @@
 
 	fd = open(FULLPATH, O_RDWR);
 	ASSERT_LE(0, fd) << strerror(errno);
-	EXPECT_EQ(EINVAL, posix_fallocate(fd, offset, length));
+	EXPECT_EQ(EOPNOTSUPP, posix_fallocate(fd, offset, length));
 
 	leak(fd);
 }