diff --git a/Userland/Libraries/LibJS/Tests/builtins/RegExp/RegExp.prototype.exec.js b/Userland/Libraries/LibJS/Tests/builtins/RegExp/RegExp.prototype.exec.js
index 6f91ec3900..535bfa7268 100644
--- a/Userland/Libraries/LibJS/Tests/builtins/RegExp/RegExp.prototype.exec.js
+++ b/Userland/Libraries/LibJS/Tests/builtins/RegExp/RegExp.prototype.exec.js
@@ -119,3 +119,11 @@ test("named capture group with two '?' qualifiers", () => {
     expect(res[1]).toBeUndefined();
     expect(res.groups.foo).toBeUndefined();
 });
+
+// #6042
+test("non-greedy brace quantifier", () => {
+    let res = /a[a-z]{2,4}?/.exec("abcdefghi");
+
+    expect(res.length).toBe(1);
+    expect(res[0]).toBe("abc");
+});
diff --git a/Userland/Libraries/LibRegex/RegexByteCode.h b/Userland/Libraries/LibRegex/RegexByteCode.h
index da9706fae2..2b1419a003 100644
--- a/Userland/Libraries/LibRegex/RegexByteCode.h
+++ b/Userland/Libraries/LibRegex/RegexByteCode.h
@@ -362,26 +362,28 @@ public:
         // LABEL _END = alterantive_bytecode.size
     }
 
-    void insert_bytecode_repetition_min_max(ByteCode& bytecode_to_repeat, size_t minimum, Optional<size_t> maximum)
+    void insert_bytecode_repetition_min_max(ByteCode& bytecode_to_repeat, size_t minimum, Optional<size_t> maximum, bool greedy = true)
     {
         ByteCode new_bytecode;
         new_bytecode.insert_bytecode_repetition_n(bytecode_to_repeat, minimum);
 
         if (maximum.has_value()) {
+            auto jump_kind = static_cast<ByteCodeValueType>(greedy ? OpCodeId::ForkStay : OpCodeId::ForkJump);
             if (maximum.value() > minimum) {
                 auto diff = maximum.value() - minimum;
-                new_bytecode.empend(static_cast<ByteCodeValueType>(OpCodeId::ForkStay));
+                new_bytecode.empend(jump_kind);
                 new_bytecode.empend(diff * (bytecode_to_repeat.size() + 2)); // Jump to the _END label
 
                 for (size_t i = 0; i < diff; ++i) {
                     new_bytecode.append(bytecode_to_repeat);
-                    new_bytecode.empend(static_cast<ByteCodeValueType>(OpCodeId::ForkStay));
+                    new_bytecode.empend(jump_kind);
                     new_bytecode.empend((diff - i - 1) * (bytecode_to_repeat.size() + 2)); // Jump to the _END label
                 }
             }
         } else {
             // no maximum value set, repeat finding if possible
-            new_bytecode.empend(static_cast<ByteCodeValueType>(OpCodeId::ForkJump));
+            auto jump_kind = static_cast<ByteCodeValueType>(greedy ? OpCodeId::ForkJump : OpCodeId::ForkStay);
+            new_bytecode.empend(jump_kind);
             new_bytecode.empend(-bytecode_to_repeat.size() - 2); // Jump to the last iteration
         }
 
diff --git a/Userland/Libraries/LibRegex/RegexParser.cpp b/Userland/Libraries/LibRegex/RegexParser.cpp
index 97f201cae0..54400f958b 100644
--- a/Userland/Libraries/LibRegex/RegexParser.cpp
+++ b/Userland/Libraries/LibRegex/RegexParser.cpp
@@ -968,10 +968,6 @@ bool ECMA262Parser::parse_quantifier(ByteCode& stack, size_t& match_length_minim
     }
 
     if (match(TokenType::Questionmark)) {
-        if (repetition_mark == Repetition::Explicit) {
-            set_error(Error::InvalidRepetitionMarker);
-            return false;
-        }
         consume();
         ungreedy = true;
     }
@@ -990,7 +986,7 @@ bool ECMA262Parser::parse_quantifier(ByteCode& stack, size_t& match_length_minim
         match_length_minimum = 0;
         break;
     case Repetition::Explicit:
-        new_bytecode.insert_bytecode_repetition_min_max(stack, repeat_min.value(), repeat_max);
+        new_bytecode.insert_bytecode_repetition_min_max(stack, repeat_min.value(), repeat_max, !ungreedy);
         match_length_minimum *= repeat_min.value();
         break;
     case Repetition::None: