diff --git a/doc/conf.py b/doc/conf.py
index 5028580e..de716d07 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -52,7 +52,7 @@
 # The short X.Y version.
 version = '2.0'
 # The full version, including alpha/beta/rc tags.
-release = '2.0.2'
+release = '2.0.3'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/examples/pseudoknot_analyzer.py b/examples/pseudoknot_analyzer.py
index be8177b0..f036d66c 100755
--- a/examples/pseudoknot_analyzer.py
+++ b/examples/pseudoknot_analyzer.py
@@ -90,6 +90,10 @@ def identification_pseudoknot(rna, without_pk, with_pk, unfold, minlength):
     dotbracket  = dotbracket.condensed()
     log.info("Condensed-bracket-structure: {}".format(dotbracket))
 
+    if set(dotbracket)-set("()[]{}<>"):
+        raise ValueError("Pseudoknots with more than 4 types of "
+                         "brackets are not supported.")
+
     #discard every structure without pseudoknot
     if not any (pk in dotbracket for pk in PK_CHECK):
         without_pk += 1
diff --git a/forgi/__init__.py b/forgi/__init__.py
index 293ef561..e8e4fe0a 100644
--- a/forgi/__init__.py
+++ b/forgi/__init__.py
@@ -20,8 +20,8 @@
 
 __author__ = "Bernhard C. Thiel, Peter Kerpedjiev"
 __copyright__ = "Copyright 2012 - 2019"
-__license__ = "GNU Affero GPL v 3.0"
-__version__ = "2.0.2"
+__license__ = "GNU GPL v 3.0"
+__version__ = "2.0.3"
 __maintainer__ = "Bernhard C. Thiel"
 __email__ = "thiel@tbi.univie.ac.at"
 
diff --git a/setup.py b/setup.py
index ebd2316b..773dc34a 100644
--- a/setup.py
+++ b/setup.py
@@ -84,7 +84,7 @@ def build_extension(self, ext):
       "zip_safe":False,
       "cmdclass":{'build_py': build_py, 'build_ext':construct_build_ext(build_ext)},
       "name":'forgi',
-      "version":'2.0.2',
+      "version":'2.0.3',
       "description":'RNA Graph Library',
       "author":'Bernhard Thiel, Peter Kerpedjiev',
       "author_email":'thiel@tbi.univie.ac.at',