diff --git a/pkgs/development/libraries/gtksourceview/4.x.nix b/pkgs/development/libraries/gtksourceview/4.x.nix
index b7828de45585..a72229237fbb 100644
--- a/pkgs/development/libraries/gtksourceview/4.x.nix
+++ b/pkgs/development/libraries/gtksourceview/4.x.nix
@@ -70,6 +70,13 @@ stdenv.mkDerivation rec {
     dbus
   ];
 
+  postPatch = ''
+    # https://gitlab.gnome.org/GNOME/gtksourceview/-/merge_requests/295
+    # build: drop unnecessary vapigen check
+    substituteInPlace meson.build \
+      --replace "if generate_vapi" "if false"
+  '';
+
   # Broken by PCRE 2 bump in GLib.
   # https://gitlab.gnome.org/GNOME/gtksourceview/-/issues/283
   doCheck = false;
diff --git a/pkgs/development/libraries/gtksourceview/5.x.nix b/pkgs/development/libraries/gtksourceview/5.x.nix
index 25bd8127a546..d3b1cc42a12f 100644
--- a/pkgs/development/libraries/gtksourceview/5.x.nix
+++ b/pkgs/development/libraries/gtksourceview/5.x.nix
@@ -74,6 +74,13 @@ stdenv.mkDerivation rec {
     "-Dgtk_doc=true"
   ];
 
+  postPatch = ''
+    # https://gitlab.gnome.org/GNOME/gtksourceview/-/merge_requests/295
+    # build: drop unnecessary vapigen check
+    substituteInPlace meson.build \
+      --replace "if generate_vapi" "if false"
+  '';
+
   doCheck = stdenv.isLinux;
 
   checkPhase = ''