diff --git a/academic/ViennaRNA/ViennaRNA.SlackBuild b/academic/ViennaRNA/ViennaRNA.SlackBuild
index 42ae76bbd7..aecfae4f20 100644
--- a/academic/ViennaRNA/ViennaRNA.SlackBuild
+++ b/academic/ViennaRNA/ViennaRNA.SlackBuild
@@ -82,6 +82,9 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
   -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+# https://github.com/ViennaRNA/ViennaRNA/issues/243
+patch -p1 < $CWD/swig_4.2.0.txt
+
 # You can configure some ViennaRNA features that are (not) compiled by default.
 # See the README.md for details. You can enable/disable a these features by
 # passing variables to the script (VAR=yes/no ./ViennaRNA.SlackBuild).
diff --git a/academic/ViennaRNA/swig_4.2.0.txt b/academic/ViennaRNA/swig_4.2.0.txt
new file mode 100644
index 0000000000..80c1ba2b82
--- /dev/null
+++ b/academic/ViennaRNA/swig_4.2.0.txt
@@ -0,0 +1,22 @@
+Description: rewriting code to build against swig 4.2.0
+Author: Pierre Gruet <pgt@debian.org>
+Forwarded: no
+Last-Update: 2024-07-26
+
+--- a/interfaces/inverse.i
++++ b/interfaces/inverse.i
+@@ -78,7 +78,14 @@
+ #ifdef SWIGPYTHON
+ %typemap(varin) char * symbolset {
+   free(symbolset);
++
++#if SWIG_VERSION >= 0x040200
++  PyObject *pbytes = NULL;
++  symbolset = strdup(SWIG_PyUnicode_AsUTF8AndSize($input, NULL, &pbytes));
++  Py_XDECREF(pbytes);
++#else
+   symbolset = strdup(SWIG_Python_str_AsChar($input));
++#endif
+ }
+ 
+ %typemap(varout) char * symbolset {