diff --git a/pkgs/development/libraries/pyotherside/default.nix b/pkgs/development/libraries/pyotherside/default.nix
index 481093cbe188..33fe7ee169e0 100644
--- a/pkgs/development/libraries/pyotherside/default.nix
+++ b/pkgs/development/libraries/pyotherside/default.nix
@@ -5,11 +5,15 @@
   python3,
   qmake,
   qtbase,
-  qtquickcontrols,
+  qtdeclarative,
+  qtquickcontrols ? null, # Qt6: merged into qtdeclarative
   qtsvg,
   ncurses,
 }:
 
+let
+  withQt6 = lib.strings.versionAtLeast qtbase.version "6";
+in
 stdenv.mkDerivation rec {
   pname = "pyotherside";
   version = "1.6.2";
@@ -21,11 +25,26 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-2OYVULNW9EzssqodiVtL2EmhTSbefXpLkub3zFvNwNo=";
   };
 
+  postPatch = ''
+    substituteInPlace qtquicktests/run \
+      --replace-fail \
+        'exec ./qtquicktests' \
+        'exec ./${
+          if stdenv.hostPlatform.isDarwin then
+            "qtquicktests.app/Contents/MacOS/qtquicktests"
+          else
+            "qtquicktests"
+        }' \
+      --replace-fail \
+        '-plugins ../src' \
+        '-plugins ../src -import $out/${qtbase.qtQmlPrefix} -import ${lib.getBin qtdeclarative}/${qtbase.qtQmlPrefix}'
+  '';
+
   nativeBuildInputs = [ qmake ];
   buildInputs = [
     python3
     qtbase
-    qtquickcontrols
+    (if withQt6 then qtdeclarative else qtquickcontrols)
     qtsvg
     ncurses
   ];
@@ -35,10 +54,35 @@ stdenv.mkDerivation rec {
   patches = [ ./qml-path.patch ];
   installTargets = [ "sub-src-install_subtargets" ];
 
+  doCheck = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+
+  checkPhase = ''
+    runHook preCheck
+
+    export QT_QPA_PLATFORM=minimal
+    export QT_PLUGIN_PATH=${lib.getBin qtbase}/${qtbase.qtPluginPrefix}
+    ./tests/tests
+
+    runHook postCheck
+  '';
+
+  doInstallCheck = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+
+  installCheckPhase = ''
+    runHook preInstallCheck
+
+    pushd qtquicktests
+    ./run
+    popd
+
+    runHook postInstallCheck
+  '';
+
   meta = {
-    description = "Asynchronous Python 3 Bindings for Qt 5";
+    description = "Asynchronous Python 3 Bindings for Qt ${lib.versions.major qtbase.version}";
     homepage = "https://thp.io/2011/pyotherside/";
     license = lib.licenses.isc;
     maintainers = [ lib.maintainers.mic92 ];
+    platforms = lib.platforms.unix ++ lib.platforms.windows;
   };
 }
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index a0449bd200b5..7c03c05c46ae 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -1738,6 +1738,7 @@ mapAliases {
   pyCA = warnAlias "'pyCA' was renamed to 'pyca'" pyca; # Added 2026-02-12
   pyload-ng = throw "'pyload-ng' has been removed due to vulnerabilities and being unmaintained"; # Added 2026-03-21
   pyo3-pack = throw "'pyo3-pack' has been renamed to/replaced by 'maturin'"; # Converted to throw 2025-10-27
+  pyotherside = warnAlias "'pyotherside' has been renamed to 'libsForQt5.pyotherside'. A Qt6 build is available at 'qt6Packages.pyotherside'."; # Added 2026-03-27
   pypolicyd-spf = throw "'pypolicyd-spf' has been renamed to/replaced by 'spf-engine'"; # Converted to throw 2025-10-27
   python3Full = throw "python3Full has been removed. Bluetooth support is now enabled by default. The tkinter package is available within the package set."; # Added 2025-08-30
   python311Full = throw "python311Full has been removed. Bluetooth support is now enabled by default. The tkinter package is available within the package set."; # Added 2025-08-30
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 9b4018f7b1a9..c100cad36f44 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -7117,8 +7117,6 @@ with pkgs;
 
   pth = if stdenv.hostPlatform.isMusl then npth else gnupth;
 
-  pyotherside = libsForQt5.callPackage ../development/libraries/pyotherside { };
-
   qbs = libsForQt5.callPackage ../development/tools/build-managers/qbs { };
 
   qdjango = libsForQt5.callPackage ../development/libraries/qdjango { };
diff --git a/pkgs/top-level/qt5-packages.nix b/pkgs/top-level/qt5-packages.nix
index 1a52c4faa1be..cc23ae2fbb92 100644
--- a/pkgs/top-level/qt5-packages.nix
+++ b/pkgs/top-level/qt5-packages.nix
@@ -154,6 +154,8 @@ makeScopeWithSplicing' {
 
         pulseaudio-qt = callPackage ../development/libraries/pulseaudio-qt { };
 
+        pyotherside = callPackage ../development/libraries/pyotherside { };
+
         qca = callPackage ../development/libraries/qca {
           inherit (libsForQt5) qtbase;
         };
diff --git a/pkgs/top-level/qt6-packages.nix b/pkgs/top-level/qt6-packages.nix
index cc1b5fec45b7..d17adae73183 100644
--- a/pkgs/top-level/qt6-packages.nix
+++ b/pkgs/top-level/qt6-packages.nix
@@ -92,6 +92,8 @@ makeScopeWithSplicing' {
 
       maplibre-native-qt = callPackage ../development/libraries/maplibre-native-qt { };
 
+      pyotherside = callPackage ../development/libraries/pyotherside { };
+
       qca = callPackage ../development/libraries/qca {
         inherit (qt6) qtbase qt5compat;
       };