diff --git a/webmention.go b/webmention.go
index 41496d8..ee84839 100644
--- a/webmention.go
+++ b/webmention.go
@@ -86,7 +86,7 @@ func extractMention(r *http.Request) (*mention, error) {
 
 func (db *database) webmentionExists(source, target string) bool {
 	result := 0
-	row, err := db.queryRow("select exists(select 1 from webmentions where source = ? and target = ?)", source, target)
+	row, err := db.queryRow("select exists(select 1 from webmentions where lower(source) = lower(@source) and lower(target) = lower(@target))", sql.Named("source", source), sql.Named("target", target))
 	if err != nil {
 		return false
 	}
@@ -143,7 +143,7 @@ func buildWebmentionsQuery(config *webmentionsRequestConfig) (query string, args
 	if config != nil {
 		filter = "where 1 = 1"
 		if config.target != "" {
-			filter += " and target = @target"
+			filter += " and lower(target) = lower(@target)"
 			args = append(args, sql.Named("target", config.target))
 		}
 		if config.status != "" {
@@ -151,8 +151,8 @@ func buildWebmentionsQuery(config *webmentionsRequestConfig) (query string, args
 			args = append(args, sql.Named("status", config.status))
 		}
 		if config.sourcelike != "" {
-			filter += " and source like @sourcelike"
-			args = append(args, sql.Named("sourcelike", "%"+config.sourcelike+"%"))
+			filter += " and lower(source) like @sourcelike"
+			args = append(args, sql.Named("sourcelike", "%"+strings.ToLower(config.sourcelike)+"%"))
 		}
 		if config.id != 0 {
 			filter += " and id = @id"
diff --git a/webmentionVerification.go b/webmentionVerification.go
index 415538d..eb4f581 100644
--- a/webmentionVerification.go
+++ b/webmentionVerification.go
@@ -98,7 +98,7 @@ func (a *goBlog) verifyMention(m *mention) error {
 	}
 	newStatus := webmentionStatusVerified
 	if a.db.webmentionExists(m.Source, m.Target) {
-		_, err = a.db.exec("update webmentions set status = @status, title = @title, content = @content, author = @author where source = @source and target = @target",
+		_, err = a.db.exec("update webmentions set status = @status, title = @title, content = @content, author = @author where lower(source) = lower(@source) and lower(target) = lower(@target)",
 			sql.Named("status", newStatus), sql.Named("title", m.Title), sql.Named("content", m.Content), sql.Named("author", m.Author), sql.Named("source", m.Source), sql.Named("target", m.Target))
 	} else {
 		_, err = a.db.exec("insert into webmentions (source, target, created, status, title, content, author) values (@source, @target, @created, @status, @title, @content, @author)",
@@ -156,7 +156,7 @@ func (m *mention) fill(mf *microformats.Microformat) bool {
 		// Check URL
 		if url, ok := mf.Properties["url"]; ok && len(url) > 0 {
 			if url0, ok := url[0].(string); ok {
-				if url0 != m.Source {
+				if strings.ToLower(url0) != strings.ToLower(m.Source) {
 					// Not correct URL
 					return false
 				}