diff --git a/pkgs/applications/science/math/sage/sage-src.nix b/pkgs/applications/science/math/sage/sage-src.nix
index bf31164417cb..1fb605b35998 100644
--- a/pkgs/applications/science/math/sage/sage-src.nix
+++ b/pkgs/applications/science/math/sage/sage-src.nix
@@ -87,6 +87,14 @@ stdenv.mkDerivation rec {
       rev = "2959ac792ebd6107fe87c9af1541083de5ba02d6";
       sha256 = "sha256-bWIpEGir9Kawak5CJegBMNcHm/CqhWmdru+emeSsvO0=";
     })
+
+    # fix intermittent errors in doctest/test.py: https://trac.sagemath.org/ticket/26912
+    (fetchSageDiff {
+      base = "9.3.beta8";
+      name = "set-cysignals-crash-ndebug.patch";
+      rev = "ca5257a5d0f32efc9f8f07e126020856270b1a18";
+      sha256 = "sha256-KViw63xE3O0eUiOYzoxNrr4NL+csql9GPJLDJCf/EZs=";
+    })
   ];
 
   # Patches needed because of package updates. We could just pin the versions of