diff --git a/pkgs/applications/audio/zynaddsubfx/ZynLogo.svg b/pkgs/by-name/zy/zynaddsubfx/ZynLogo.svg
similarity index 100%
rename from pkgs/applications/audio/zynaddsubfx/ZynLogo.svg
rename to pkgs/by-name/zy/zynaddsubfx/ZynLogo.svg
diff --git a/pkgs/applications/audio/zynaddsubfx/mruby-zest/default.nix b/pkgs/by-name/zy/zynaddsubfx/mruby-zest/default.nix
similarity index 84%
rename from pkgs/applications/audio/zynaddsubfx/mruby-zest/default.nix
rename to pkgs/by-name/zy/zynaddsubfx/mruby-zest/default.nix
index ff9ce3f10486..5a86f6e88d2c 100644
--- a/pkgs/applications/audio/zynaddsubfx/mruby-zest/default.nix
+++ b/pkgs/by-name/zy/zynaddsubfx/mruby-zest/default.nix
@@ -1,6 +1,6 @@
 {
   lib,
-  stdenv,
+  gcc14Stdenv,
   fetchFromGitHub,
   bison,
   pkg-config,
@@ -11,7 +11,10 @@
   libx11,
 }:
 
-stdenv.mkDerivation (finalAttrs: {
+# UI becomes unresponsive when built with GCC 15
+# (building with -std=gnu17 does not fix the issue)
+# https://github.com/mruby-zest/mruby-zest-build/issues/127
+gcc14Stdenv.mkDerivation (finalAttrs: {
   pname = "mruby-zest";
   version = "3.0.6";
 
@@ -20,7 +23,7 @@ stdenv.mkDerivation (finalAttrs: {
     repo = "mruby-zest-build";
     tag = finalAttrs.version;
     fetchSubmodules = true;
-    sha256 = "sha256-rIb6tQimwrUj+623IU5zDyKNWsNYYBElLQClOsP+5Dc=";
+    hash = "sha256-rIb6tQimwrUj+623IU5zDyKNWsNYYBElLQClOsP+5Dc=";
   };
 
   patches = [
diff --git a/pkgs/applications/audio/zynaddsubfx/mruby-zest/force-cxx-as-linker.patch b/pkgs/by-name/zy/zynaddsubfx/mruby-zest/force-cxx-as-linker.patch
similarity index 100%
rename from pkgs/applications/audio/zynaddsubfx/mruby-zest/force-cxx-as-linker.patch
rename to pkgs/by-name/zy/zynaddsubfx/mruby-zest/force-cxx-as-linker.patch
diff --git a/pkgs/applications/audio/zynaddsubfx/default.nix b/pkgs/by-name/zy/zynaddsubfx/package.nix
similarity index 97%
rename from pkgs/applications/audio/zynaddsubfx/default.nix
rename to pkgs/by-name/zy/zynaddsubfx/package.nix
index 7c5506413386..03ae96580f2e 100644
--- a/pkgs/applications/audio/zynaddsubfx/default.nix
+++ b/pkgs/by-name/zy/zynaddsubfx/package.nix
@@ -11,7 +11,7 @@
   pkg-config,
 
   # Required dependencies
-  fftw,
+  fftwSinglePrec,
   liblo,
   minixml,
   zlib,
@@ -31,7 +31,7 @@
   sndio,
 
   # Optional GUI dependencies
-  guiModule ? "off",
+  guiModule ? "zest",
   cairo,
   fltk,
   libGL,
@@ -100,7 +100,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   buildInputs = [
-    fftw
+    fftwSinglePrec
     liblo
     minixml
     zlib
@@ -184,9 +184,12 @@ stdenv.mkDerivation (finalAttrs: {
       --prefix LD_LIBRARY_PATH : ${mruby-zest}
   '';
 
+  passthru = {
+    inherit mruby-zest;
+  };
+
   meta = {
     description = "High quality software synthesizer (${guiName} GUI)";
-    mainProgram = "zynaddsubfx";
     homepage =
       if guiModule == "zest" then
         "https://zynaddsubfx.sourceforge.io/zyn-fusion.html"
@@ -196,6 +199,7 @@ stdenv.mkDerivation (finalAttrs: {
     license = lib.licenses.gpl2Plus;
     maintainers = with lib.maintainers; [ kira-bruneau ];
     platforms = lib.platforms.all;
+    mainProgram = "zynaddsubfx";
 
     # On macOS:
     # - Tests don't compile (ld: unknown option: --no-as-needed)
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 6e9a2b2fdf62..f5046a7f2fea 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -11000,11 +11000,6 @@ with pkgs;
     SDL_image = SDL_image.override { SDL = SDL_sixel; };
   };
 
-  zynaddsubfx = callPackage ../applications/audio/zynaddsubfx {
-    guiModule = "zest";
-    fftw = fftwSinglePrec;
-  };
-
   zynaddsubfx-fltk = zynaddsubfx.override {
     guiModule = "fltk";
   };