diff --git a/tests/qemu-iotests/149 b/tests/qemu-iotests/149
index 328fd05a4c..d49646ca60 100755
--- a/tests/qemu-iotests/149
+++ b/tests/qemu-iotests/149
@@ -230,6 +230,18 @@ def create_image(config, size_mb):
         fn.truncate(size_mb * 1024 * 1024)
 
 
+def check_cipher_support(config, output):
+    """Check the output of qemu-img or qemu-io for mention of the respective
+    cipher algorithm being unsupported, and if so, skip this test.
+    (Returns `output` for convenience.)"""
+
+    if 'Unsupported cipher algorithm' in output:
+        iotests.notrun('Unsupported cipher algorithm '
+                       f'{config.cipher}-{config.keylen}-{config.mode}; '
+                       'consider configuring qemu with a different crypto '
+                       'backend')
+    return output
+
 def qemu_img_create(config, size_mb):
     """Create and format a disk image with LUKS using qemu-img"""
 
@@ -253,7 +265,8 @@ def qemu_img_create(config, size_mb):
             "%dM" % size_mb]
 
     iotests.log("qemu-img " + " ".join(args), filters=[iotests.filter_test_dir])
-    iotests.log(iotests.qemu_img_pipe(*args), filters=[iotests.filter_test_dir])
+    iotests.log(check_cipher_support(config, iotests.qemu_img_pipe(*args)),
+                filters=[iotests.filter_test_dir])
 
 def qemu_io_image_args(config, dev=False):
     """Get the args for access an image or device with qemu-io"""
@@ -279,8 +292,8 @@ def qemu_io_write_pattern(config, pattern, offset_mb, size_mb, dev=False):
     args = ["-c", "write -P 0x%x %dM %dM" % (pattern, offset_mb, size_mb)]
     args.extend(qemu_io_image_args(config, dev))
     iotests.log("qemu-io " + " ".join(args), filters=[iotests.filter_test_dir])
-    iotests.log(iotests.qemu_io(*args), filters=[iotests.filter_test_dir,
-                                                 iotests.filter_qemu_io])
+    iotests.log(check_cipher_support(config, iotests.qemu_io(*args)),
+                filters=[iotests.filter_test_dir, iotests.filter_qemu_io])
 
 
 def qemu_io_read_pattern(config, pattern, offset_mb, size_mb, dev=False):
@@ -291,8 +304,8 @@ def qemu_io_read_pattern(config, pattern, offset_mb, size_mb, dev=False):
     args = ["-c", "read -P 0x%x %dM %dM" % (pattern, offset_mb, size_mb)]
     args.extend(qemu_io_image_args(config, dev))
     iotests.log("qemu-io " + " ".join(args), filters=[iotests.filter_test_dir])
-    iotests.log(iotests.qemu_io(*args), filters=[iotests.filter_test_dir,
-                                                 iotests.filter_qemu_io])
+    iotests.log(check_cipher_support(config, iotests.qemu_io(*args)),
+                filters=[iotests.filter_test_dir, iotests.filter_qemu_io])
 
 
 def test_once(config, qemu_img=False):