diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3cd9432d455..f84c23f434c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,7 @@ Note that this project **does not** adhere to [Semantic Versioning](http://semve
 - We fixed an issue where sort on numeric cases was broken. [#6349](https://github.com/JabRef/jabref/issues/6349)
 - We fixed an issue where an "Not on FX thread" exception occured when saving on linux [#6453](https://github.com/JabRef/jabref/issues/6453)
 - We fixed an issue where the library sort order was lost. [#6091](https://github.com/JabRef/jabref/issues/6091)
+- We fixed an issue where brackets in regular expressions were not working. [6469](https://github.com/JabRef/jabref/pull/6469)
 
 ### Removed
 
diff --git a/src/main/java/org/jabref/logic/bibtexkeypattern/BracketedPattern.java b/src/main/java/org/jabref/logic/bibtexkeypattern/BracketedPattern.java
index c90204eee67..316de3b4dc3 100644
--- a/src/main/java/org/jabref/logic/bibtexkeypattern/BracketedPattern.java
+++ b/src/main/java/org/jabref/logic/bibtexkeypattern/BracketedPattern.java
@@ -106,40 +106,72 @@ public static String expandBrackets(String pattern, Character keywordDelimiter,
         Objects.requireNonNull(pattern);
         Objects.requireNonNull(entry);
         StringBuilder sb = new StringBuilder();
-        StringTokenizer st = new StringTokenizer(pattern, "\\[]", true);
+        StringTokenizer st = new StringTokenizer(pattern, "\\[]\"", true);
 
         while (st.hasMoreTokens()) {
             String token = st.nextToken();
-            if ("\\".equals(token)) {
-                if (st.hasMoreTokens()) {
-                    sb.append(st.nextToken());
-                }
-                // FIXME: else -> raise exception or log? (S.G.)
-            } else {
-                if ("[".equals(token)) {
-                    // Fetch the next token after the '[':
+            if ("\"".equals(token)) {
+                sb.append(token);
+                while (st.hasMoreTokens()) {
                     token = st.nextToken();
-                    List<String> fieldParts = parseFieldMarker(token);
-                    // check whether there is a modifier on the end such as
-                    // ":lower":
-                    if (fieldParts.size() <= 1) {
-                        sb.append(getFieldValue(entry, token, keywordDelimiter, database));
-                    } else {
-                        // apply modifiers:
-                        String fieldValue = getFieldValue(entry, fieldParts.get(0), keywordDelimiter, database);
-                        sb.append(applyModifiers(fieldValue, fieldParts, 1));
+                    sb.append(token);
+                    if ("\"".equals(token)) {
+                        break;
                     }
-                    // Fetch and discard the closing ']'
+                }
+            } else {
+                if ("\\".equals(token)) {
                     if (st.hasMoreTokens()) {
+                        sb.append(st.nextToken());
+                    }
+                    // FIXME: else -> raise exception or log? (S.G.)
+                } else {
+                    if ("[".equals(token)) {
+                        Boolean foundClosingBracket = false;
+                        // Fetch the next token after the '[':
                         token = st.nextToken();
+                        if ("]".equals(token)) {
+                            LOGGER.warn("Found empty brackets \"[]\" in '" + pattern + "'");
+                            foundClosingBracket = true;
+                        }
+                        // make sure to read until the next ']'
+                        while (st.hasMoreTokens() && !foundClosingBracket) {
+                            String subtoken = st.nextToken();
+                            // I the beginning of a quote is found, include the content in the original token
+                            if ("\"".equals(subtoken)) {
+                                token = token + subtoken;
+                                while (st.hasMoreTokens()) {
+                                    subtoken = st.nextToken();
+                                    token = token + subtoken;
+                                    if ("\"".equals(subtoken)) {
+                                        break;
+                                    }
+                                }
+                            } else {
+                                if ("]".equals(subtoken)) {
+                                    foundClosingBracket = true;
+                                    break;
+                                } else {
+                                    token = token + subtoken;
+                                }
+                            }
+                        }
+                        if (!foundClosingBracket) {
+                            LOGGER.warn("Missing closing bracket ']' in '" + pattern + "'");
+                        }
+                        List<String> fieldParts = parseFieldMarker(token);
+                        // check whether there is a modifier on the end such as
+                        // ":lower":
+                        if (fieldParts.size() <= 1) {
+                            sb.append(getFieldValue(entry, token, keywordDelimiter, database));
+                        } else {
+                            // apply modifiers:
+                            String fieldValue = getFieldValue(entry, fieldParts.get(0), keywordDelimiter, database);
+                            sb.append(applyModifiers(fieldValue, fieldParts, 1));
+                        }
                     } else {
-                        token = "";
-                    }
-                    if (!"]".equals(token)) {
-                        LOGGER.warn("Missing closing bracket ']' in '" + pattern + "'");
+                        sb.append(token);
                     }
-                } else {
-                    sb.append(token);
                 }
             }
         }
diff --git a/src/test/java/org/jabref/logic/util/BracketedPatternTest.java b/src/test/java/org/jabref/logic/util/BracketedPatternTest.java
index 41bfbad9622..e142c4fb270 100644
--- a/src/test/java/org/jabref/logic/util/BracketedPatternTest.java
+++ b/src/test/java/org/jabref/logic/util/BracketedPatternTest.java
@@ -241,4 +241,16 @@ void regularExpressionReplace() {
         assertEquals("2003-JabRef Science",
                 BracketedPattern.expandBrackets("[year]-[journal:regex(\"Organization\",\"JabRef\")]", ';', dbentry, database));
     }
+
+    @Test
+    void regularExpressionWithBrackets() {
+        assertEquals("2003-JabRef Science",
+                BracketedPattern.expandBrackets("[year]-[journal:regex(\"[OX]rganization\",\"JabRef\")]", ';', dbentry, database));
+    }
+
+    @Test
+    void testEmptyBrackets() {
+        assertEquals("2003-Organization Science",
+                BracketedPattern.expandBrackets("[year][]-[journal]", ';', dbentry, database));
+    }
 }