diff --git a/compose/service/attachment.go b/compose/service/attachment.go
index 20fa64663..616ad3e29 100644
--- a/compose/service/attachment.go
+++ b/compose/service/attachment.go
@@ -6,7 +6,6 @@ import (
 	"image"
 	"image/gif"
 	"io"
-	"net/http"
 	"path"
 	"regexp"
 	"strings"
@@ -20,6 +19,7 @@ import (
 	systemService "github.com/cortezaproject/corteza-server/system/service"
 	"github.com/disintegration/imaging"
 	"github.com/edwvee/exiffix"
+	"github.com/gabriel-vasile/mimetype"
 )
 
 const (
@@ -510,21 +510,22 @@ func (svc attachment) create(ctx context.Context, s store.ComposeAttachments, na
 	return nil
 }
 
-func (svc attachment) extractMimetype(file io.ReadSeeker) (mimetype string, err error) {
+func (svc attachment) extractMimetype(file io.ReadSeeker) (mType string, err error) {
 	if _, err = file.Seek(0, 0); err != nil {
 		return
 	}
 
 	// Make sure we rewind when we're done
-	defer file.Seek(0, 0)
+	defer func(file io.ReadSeeker, offset int64, whence int) {
+		_, _ = file.Seek(offset, whence)
+	}(file, 0, 0)
 
-	// See http.DetectContentType about 512 bytes
-	var buf = make([]byte, 512)
-	if _, err = file.Read(buf); err != nil {
+	var mime *mimetype.MIME
+	if mime, err = mimetype.DetectReader(file); err != nil {
 		return
 	}
 
-	return http.DetectContentType(buf), nil
+	return mime.String(), nil
 }
 
 func (svc attachment) processImage(original io.ReadSeeker, att *types.Attachment) (err error) {
diff --git a/tests/compose/page_test.go b/tests/compose/page_test.go
index 983681398..59d013040 100644
--- a/tests/compose/page_test.go
+++ b/tests/compose/page_test.go
@@ -369,9 +369,7 @@ func TestPageAttachment(t *testing.T) {
 
 	// one megabyte limit
 	systemService.CurrentSettings.Compose.Page.Attachments.MaxSize = 1
-	systemService.CurrentSettings.Compose.Page.Attachments.Mimetypes = []string{
-		"application/octet-stream",
-	}
+	systemService.CurrentSettings.Compose.Page.Attachments.Mimetypes = []string{}
 
 	cc := []struct {
 		name  string
@@ -419,7 +417,7 @@ func TestPageAttachment(t *testing.T) {
 			"numbers.gif",
 			"image/gif",
 			map[string]string{},
-			helpers.AssertError("attachment.errors.notAllowedToUploadThisType"),
+			helpers.AssertError("attachment.errors.failedToProcessImage"),
 		},
 	}
 
diff --git a/tests/compose/record_test.go b/tests/compose/record_test.go
index 451129bfc..56eebaa54 100644
--- a/tests/compose/record_test.go
+++ b/tests/compose/record_test.go
@@ -796,6 +796,13 @@ func TestRecordAttachment(t *testing.T) {
 			},
 		},
 		&types.ModuleField{Name: "str", Kind: "String"},
+		&types.ModuleField{
+			Name: "csv_only",
+			Kind: "File",
+			Options: types.ModuleFieldOptions{
+				"mimetypes": "text/csv",
+			},
+		},
 	)
 
 	xxlBlob := bytes.Repeat([]byte("0"), maxSizeLimit*1_000_000+1)
@@ -803,6 +810,9 @@ func TestRecordAttachment(t *testing.T) {
 	testImgFh, err := os.ReadFile("./testdata/test.png")
 	h.noError(err)
 
+	testCsvFh, err := os.ReadFile("./testdata/test.csv")
+	h.noError(err)
+
 	defer func() {
 		// reset settings after we're done
 		systemService.CurrentSettings.Compose.Record.Attachments.MaxSize = 0
@@ -810,9 +820,7 @@ func TestRecordAttachment(t *testing.T) {
 	}()
 
 	systemService.CurrentSettings.Compose.Record.Attachments.MaxSize = maxSizeLimit
-	systemService.CurrentSettings.Compose.Record.Attachments.Mimetypes = []string{
-		"application/octet-stream",
-	}
+	systemService.CurrentSettings.Compose.Record.Attachments.Mimetypes = []string{}
 
 	cc := []struct {
 		name  string
@@ -892,7 +900,7 @@ func TestRecordAttachment(t *testing.T) {
 			"numbers.gif",
 			"image/gif",
 			map[string]string{"fieldName": "no_constraints"},
-			helpers.AssertError("attachment.errors.notAllowedToUploadThisType"),
+			helpers.AssertError("attachment.errors.failedToProcessImage"),
 		},
 		{
 			"field mimetype - ok",
@@ -910,6 +918,14 @@ func TestRecordAttachment(t *testing.T) {
 			map[string]string{"fieldName": "img_only"},
 			helpers.AssertNoErrors,
 		},
+		{
+			"csv file - ok",
+			testCsvFh,
+			"testCSV",
+			"text/csv",
+			map[string]string{"fieldName": "csv_only"},
+			helpers.AssertNoErrors,
+		},
 	}
 
 	for _, c := range cc {
diff --git a/tests/compose/testdata/test.csv b/tests/compose/testdata/test.csv
new file mode 100644
index 000000000..e7bba0d3d
--- /dev/null
+++ b/tests/compose/testdata/test.csv
@@ -0,0 +1,6 @@
+John,Doe,120 jefferson st.,Riverside, NJ, 08075
+Jack,McGinnis,220 hobo Av.,Phila, PA,09119
+"John ""Da Man""",Repici,120 Jefferson St.,Riverside, NJ,08075
+Stephen,Tyler,"7452 Terrace ""At the Plaza"" road",SomeTown,SD, 91234
+,Blankman,,SomeTown, SD, 00298
+"Joan ""the bone"", Anne",Jet,"9th, at Terrace plc",Desert City,CO,00123