diff --git a/pkgs/tools/admin/pgadmin/default.nix b/pkgs/tools/admin/pgadmin/default.nix
index 6d60aa9c0d97..d5c6932c44f8 100644
--- a/pkgs/tools/admin/pgadmin/default.nix
+++ b/pkgs/tools/admin/pgadmin/default.nix
@@ -83,6 +83,15 @@ let
         sha256 = "sha256-FZcuUBffBXXD1sCQuhaLbbkCWeYgrI1+qBOjlrrVtss=";
       };
     });
+    # flask 2.1.3 is incompatible with flask-sqlalchemy > 3
+    flask-sqlalchemy = prev.flask-sqlalchemy.overridePythonAttrs (oldAttrs: rec {
+      version = "2.5.1";
+      format = "setuptools";
+      src = oldAttrs.src.override {
+        inherit version;
+        hash = "sha256-K9pEtD58rLFdTgX/PMH4vJeTbMRkYjQkECv8LDXpWRI=";
+      };
+    });
     # pgadmin 6.18 is incompatible with the major flask-security-too update to 5.0.x
     flask-security-too = prev.flask-security-too.overridePythonAttrs (oldAttrs: rec {
       version = "4.1.5";