diff --git a/script/test-smoke.sh b/script/test-smoke.sh
index 0adf322a..e6f1c6ea 100755
--- a/script/test-smoke.sh
+++ b/script/test-smoke.sh
@@ -257,15 +257,15 @@ if [ -z "$SKIP_AWS" ]; then
   aws s3api list-parts --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID >$CMDOUT
   [ $(jq '.Parts | length' $CMDOUT) == 0 ]
   [ $(jq -r '.StorageClass' $CMDOUT) == 'STANDARD' ] # check that the result is not empty
-  ETAG1=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 10 --body /tmp/garage.2.rnd | jq .ETag)
+  ETAG1=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 1 --body /tmp/garage.2.rnd | jq .ETag)
   aws s3api list-parts --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID >$CMDOUT
   [ $(jq '.Parts | length' $CMDOUT) == 1 ]
-  [ $(jq '.Parts[0].PartNumber' $CMDOUT) == 10 ]
+  [ $(jq '.Parts[0].PartNumber' $CMDOUT) == 1 ]
   [ $(jq '.Parts[0].Size' $CMDOUT) == 5242880 ]
   [ $(jq '.Parts[0].ETag' $CMDOUT) == $ETAG1 ]
 
-  ETAG2=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 9999 --body /tmp/garage.3.rnd | jq .ETag)
-  ETAG3=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 30 --body /tmp/garage.2.rnd | jq .ETag)
+  ETAG2=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 3 --body /tmp/garage.3.rnd | jq .ETag)
+  ETAG3=$(aws s3api upload-part --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID --part-number 2 --body /tmp/garage.2.rnd | jq .ETag)
   aws s3api list-parts --bucket eprouvette --key list-parts --upload-id $UPLOAD_ID >$CMDOUT
   [ $(jq '.Parts | length' $CMDOUT) == 3 ]
   [ $(jq '.Parts[1].ETag' $CMDOUT) == $ETAG3 ]
@@ -279,15 +279,15 @@ if [ -z "$SKIP_AWS" ]; then
   "Parts": [
     {
       "ETag": $ETAG1,
-      "PartNumber": 10
+      "PartNumber": 1
     },
     {
       "ETag": $ETAG3,
-      "PartNumber": 30
+      "PartNumber": 2
     },
     {
       "ETag": $ETAG2,
-      "PartNumber": 9999
+      "PartNumber": 3
     }
   ]
 }
diff --git a/src/api/s3_put.rs b/src/api/s3_put.rs
index f52080a6..a6863cd3 100644
--- a/src/api/s3_put.rs
+++ b/src/api/s3_put.rs
@@ -559,6 +559,17 @@ pub async fn handle_complete_multipart_upload(
 		return Err(Error::InvalidPartOrder);
 	}
 
+	// Garage-specific restriction, see #204: part numbers must be
+	// consecutive starting at 1
+	if body_list_of_parts[0].part_number != 1
+		|| !body_list_of_parts
+			.iter()
+			.zip(body_list_of_parts.iter().skip(1))
+			.all(|(p1, p2)| p1.part_number + 1 == p2.part_number)
+	{
+		return Err(Error::NotImplemented("Garage does not support completing a Multipart upload with non-consecutive part numbers. This is a restriction of Garage's data model, which might be fixed in a future release. See issue #204 for more information on this topic.".into()));
+	}
+
 	// Check that the list of parts they gave us corresponds to the parts we have here
 	debug!("Expected parts from request: {:?}", body_list_of_parts);
 	debug!("Parts stored in version: {:?}", version.parts_etags.items());