diff --git a/pyam/str.py b/pyam/str.py
index f9bafca46..53a2ba4f7 100644
--- a/pyam/str.py
+++ b/pyam/str.py
@@ -4,6 +4,8 @@
 import pandas as pd
 from pandas.api.types import is_list_like
 
+REGEXP_CHARACTERS = r".^$+?()[]{}|"
+
 
 def concat_with_pipe(x, *args, cols=None):
     """Concatenate a list or pandas.Series using ``|``, drop None or numpy.nan"""
@@ -123,21 +125,17 @@ def reduce_hierarchy(x, depth):
     """
     _x = x.split("|")
     depth = len(_x) + depth - 1 if depth < 0 else depth
-    return "|".join(_x[0 : (depth + 1)])
+    return "|".join(_x[0: (depth + 1)])
 
 
 def escape_regexp(s):
     """Escape characters with specific regexp use"""
-    return (
-        str(s)
-        .replace("|", "\\|")
-        .replace(".", r"\.")  # `.` has to be replaced before `*`
-        .replace("*", ".*")
-        .replace("+", r"\+")
-        .replace("(", r"\(")
-        .replace(")", r"\)")
-        .replace("$", "\\$")
-    )
+    s = str(s)
+    for c in REGEXP_CHARACTERS:
+        s = s.replace(c, "\\" + c)
+    # pyam uses `*` as wildcard, replace with `.*` for regex
+    s = s.replace("*", ".*")
+    return s
 
 
 def is_str(x):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index af2e80b82..6b36c8994 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -78,9 +78,13 @@ def test_pattern_match_dot():
     assert (obs == [False, True]).all()
 
 
-def test_pattern_match_brackets():
-    data = pd.Series(["foo (bar)", "foo bar"])
-    values = ["foo (bar)"]
+@pytest.mark.parametrize(
+    "bracket", ("(bar)", "[bar]", "{2}")
+)
+def test_pattern_match_brackets(bracket):
+    s = f"foo {bracket}"
+    data = pd.Series([s, "foo bar"])
+    values = [s]
 
     obs = pattern_match(data, values)
     assert (obs == [True, False]).all()