diff --git a/distribution/changelog.txt b/distribution/changelog.txt
index 3f9e788e13..6bc9a3d1d8 100644
--- a/distribution/changelog.txt
+++ b/distribution/changelog.txt
@@ -13,6 +13,7 @@
 - Fix: [#24975] The Corkscrew and LIM Launched (original bug) roller coaster quarter loop tunnels are too high.
 - Fix: [#25139] Steam locomotive and tram claxons can sound louder than normal when approaching crossings that span multiple tiles.
 - Fix: [#25190] Inserting a block brake while a coaster is simulating will cause the simulation to behave strangely.
+- Fix: [#25206] System file picker does not show up on the Steam Deck.
 - Fix: [#25272] Text colour dropdown in the Banner window is too narrow, resulting in truncated labels.
 - Fix: [#25299] The Mine Train Coaster left large helix draws incorrect sprites at certain angles (original bug).
 - Fix: [#25328] Spiral Slide in Blackpool Pleasure Beach has its entrance and exit the wrong way round (bug in the original scenario).
diff --git a/src/openrct2-ui/UiContext.Linux.cpp b/src/openrct2-ui/UiContext.Linux.cpp
index b7ab3c0b94..7b2978d93a 100644
--- a/src/openrct2-ui/UiContext.Linux.cpp
+++ b/src/openrct2-ui/UiContext.Linux.cpp
@@ -20,6 +20,7 @@
     #include <openrct2/core/Path.hpp>
     #include <openrct2/core/String.hpp>
     #include <openrct2/core/StringBuilder.h>
+    #include <openrct2/core/StringTypes.h>
     #include <openrct2/localisation/Language.h>
     #include <openrct2/platform/Platform.h>
     #include <openrct2/ui/UiContext.h>
@@ -102,21 +103,22 @@ namespace OpenRCT2::Ui
 
             std::string executablePath;
             DialogType dtype = GetDialogApp(&executablePath);
-
             switch (dtype)
             {
                 case DialogType::kdialog:
                 {
-                    std::string cmd = String::stdFormat(
-                        "%s --title \"OpenRCT2\" --msgbox \"%s\"", executablePath.c_str(), message.c_str());
-                    Platform::Execute(cmd);
+                    const char* args[] = {
+                        executablePath.c_str(), "--title", "OpenRCT2", "--msgbox", message.c_str(), nullptr
+                    };
+                    Platform::Execute(args);
                     break;
                 }
                 case DialogType::zenity:
                 {
-                    std::string cmd = String::stdFormat(
-                        "%s --title=\"OpenRCT2\" --info --text=\"%s\"", executablePath.c_str(), message.c_str());
-                    Platform::Execute(cmd);
+                    const char* args[] = {
+                        executablePath.c_str(), "--title=OpenRCT2", "--info", "--text", message.c_str(), nullptr
+                    };
+                    Platform::Execute(args);
                     break;
                 }
                 default:
@@ -127,15 +129,15 @@ namespace OpenRCT2::Ui
 
         void OpenFolder(const std::string& path) override
         {
-            std::string cmd = String::stdFormat("xdg-open %s", EscapePathForShell(path).c_str());
-            Platform::Execute(cmd);
+            const char* args[] = { "xdg-open", path.c_str(), nullptr };
+            Platform::Execute(args);
         }
 
         void OpenURL(const std::string& url) override
         {
     #ifndef __EMSCRIPTEN__
-            std::string cmd = String::stdFormat("xdg-open %s", url.c_str());
-            Platform::Execute(cmd);
+            const char* args[] = { "xdg-open", url.c_str(), nullptr };
+            Platform::Execute(args);
     #else
             MAIN_THREAD_EM_ASM({ window.open(UTF8ToString($0)); }, url.c_str());
     #endif
@@ -145,19 +147,28 @@ namespace OpenRCT2::Ui
         {
             std::string result;
             std::string executablePath;
-            u8string directory = EscapePathForShell(desc.InitialDirectory + '/');
+            u8string directory = desc.InitialDirectory + '/';
             DialogType dtype = GetDialogApp(&executablePath);
             switch (dtype)
             {
                 case DialogType::kdialog:
                 {
                     std::string action = (desc.Type == FileDialogType::Open) ? "--getopenfilename" : "--getsavefilename";
-                    std::string filter = GetKDialogFilterString(desc.Filters);
-                    std::string cmd = String::stdFormat(
-                        "%s --title '%s' %s %s '%s'", executablePath.c_str(), desc.Title.c_str(), action.c_str(),
-                        directory.c_str(), filter.c_str());
+                    std::vector<std::string> filters = GetKDialogFilterString(desc.Filters);
+                    std::vector<std::string> argsVec = { executablePath, "--title", desc.Title, action, directory };
+                    for (const auto& filter : filters)
+                    {
+                        argsVec.push_back(filter);
+                    }
+                    std::vector<const char*> args;
+                    for (const auto& arg : argsVec)
+                    {
+                        args.push_back(arg.c_str());
+                    }
+                    args.push_back(nullptr);
+
                     std::string output;
-                    if (Platform::Execute(cmd, &output) == 0)
+                    if (Platform::Execute(args.data(), &output) == 0)
                     {
                         result = output;
                     }
@@ -166,17 +177,30 @@ namespace OpenRCT2::Ui
                 case DialogType::zenity:
                 {
                     std::string action = "--file-selection";
-                    std::string flags;
+                    std::vector<std::string> filters = GetZenityFilterString(desc.Filters);
+                    u8string directoryarg = String::stdFormat("--filename=%s", directory.c_str());
+                    std::vector<std::string> argsVec = { executablePath, action, directoryarg };
                     if (desc.Type == FileDialogType::Save)
                     {
-                        flags = "--confirm-overwrite --save";
+                        argsVec.push_back("--confirm-overwrite");
+                        argsVec.push_back("--save");
                     }
-                    std::string filters = GetZenityFilterString(desc.Filters);
-                    std::string cmd = String::stdFormat(
-                        "%s %s --filename=%s %s --title='%s' / %s", executablePath.c_str(), action.c_str(), directory.c_str(),
-                        flags.c_str(), desc.Title.c_str(), filters.c_str());
+                    argsVec.push_back("--title");
+                    argsVec.push_back(desc.Title);
+                    argsVec.push_back("/");
+                    for (const auto& filter : filters)
+                    {
+                        argsVec.push_back(filter);
+                    }
+                    std::vector<const char*> args;
+                    for (const auto& arg : argsVec)
+                    {
+                        args.push_back(arg.c_str());
+                    }
+                    args.push_back(nullptr);
+
                     std::string output;
-                    if (Platform::Execute(cmd, &output) == 0)
+                    if (Platform::Execute(args.data(), &output) == 0)
                     {
                         if (desc.Type == FileDialogType::Save)
                         {
@@ -219,8 +243,9 @@ namespace OpenRCT2::Ui
                 }
                 if (desc.Type == FileDialogType::Save && access(result.c_str(), F_OK) != -1 && dtype == DialogType::kdialog)
                 {
-                    std::string cmd = String::stdFormat("%s --yesno \"Overwrite %s?\"", executablePath.c_str(), result.c_str());
-                    if (Platform::Execute(cmd) != 0)
+                    u8string overwrite = String::stdFormat("Overwrite %s?", result.c_str());
+                    const char* args[] = { executablePath.c_str(), "--yesno", overwrite.c_str(), nullptr };
+                    if (Platform::Execute(args) != 0)
                     {
                         result = std::string();
                     }
@@ -241,7 +266,9 @@ namespace OpenRCT2::Ui
                     std::string output;
                     std::string cmd = String::stdFormat(
                         "%s --title '%s' --getexistingdirectory /", executablePath.c_str(), title.c_str());
-                    if (Platform::Execute(cmd, &output) == 0)
+                    const char* args[] = { executablePath.c_str(),   "--title", title.c_str(),
+                                           "--getexistingdirectory", "/",       nullptr };
+                    if (Platform::Execute(args, &output) == 0)
                     {
                         result = output;
                     }
@@ -252,7 +279,9 @@ namespace OpenRCT2::Ui
                     std::string output;
                     std::string cmd = String::stdFormat(
                         "%s --title='%s' --file-selection --directory /", executablePath.c_str(), title.c_str());
-                    if (Platform::Execute(cmd, &output) == 0)
+                    const char* args[] = { executablePath.c_str(), "--title", title.c_str(), "--file-selection",
+                                           "--directory",          "/",       nullptr };
+                    if (Platform::Execute(args, &output) == 0)
                     {
                         result = output;
                     }
@@ -306,30 +335,49 @@ namespace OpenRCT2::Ui
             {
                 case DialogType::zenity:
                 {
-                    auto sb = StringBuilder();
-                    sb.Append(String::stdFormat("zenity --list --column '' --width=%d --height=%d", width, height));
+                    std::vector<std::string> argsVec = { executablePath,
+                                                         "--list",
+                                                         "--column",
+                                                         "",
+                                                         String::stdFormat("--width=%d", width),
+                                                         String::stdFormat("--height=%d", height) };
                     for (const auto& option : options)
                     {
-                        sb.Append(String::stdFormat(" '%s'", option.c_str()));
+                        argsVec.push_back(option);
                     }
-                    sb.Append(String::stdFormat(" --title '%s' --text '%s'", title.c_str(), text.c_str()));
-
+                    argsVec.push_back("--title");
+                    argsVec.push_back(title);
+                    argsVec.push_back("--text");
+                    argsVec.push_back(text);
+                    std::vector<const char*> args;
+                    for (const auto& arg : argsVec)
+                    {
+                        args.push_back(arg.c_str());
+                    }
+                    args.push_back(nullptr);
                     std::string buff;
-                    Platform::Execute(sb.GetBuffer(), &buff);
+                    Platform::Execute(args.data(), &buff);
                     return std::find(options.begin(), options.end(), buff) - options.begin();
                 }
                 case DialogType::kdialog:
                 {
-                    auto sb = StringBuilder();
-                    sb.Append(String::stdFormat("kdialog --geometry %dx%d --title '%s' --menu ", width, height, title.c_str()));
-                    sb.Append(String::stdFormat(" '%s'", text.c_str()));
+                    std::vector<std::string> argsVec = {
+                        executablePath, "--geometry", String::stdFormat("%dx%d", width, height), "--title", title,
+                        "--menu",       text
+                    };
                     for (const auto& option : options)
                     {
-                        sb.Append(String::stdFormat(" '%s' '%s'", option.c_str(), option.c_str()));
+                        argsVec.push_back(option);
+                        argsVec.push_back(option);
                     }
-
+                    std::vector<const char*> args;
+                    for (const auto& arg : argsVec)
+                    {
+                        args.push_back(arg.c_str());
+                    }
+                    args.push_back(nullptr);
                     std::string buff;
-                    Platform::Execute(sb.GetBuffer(), &buff);
+                    Platform::Execute(args.data(), &buff);
                     return std::find(options.begin(), options.end(), buff) - options.begin();
                 }
                 default:
@@ -346,8 +394,6 @@ namespace OpenRCT2::Ui
         {
             // Prefer zenity as it offers more required features, e.g., overwrite
             // confirmation and selecting only existing files.
-            // Silence error output with 2> /dev/null to avoid confusion in the
-            // case where a user does not have zenity and/or kdialog.
             // OpenRCT2 will fall back to an SDL pop-up if the user has neither.
             if (Platform::FindApp("zenity", executablePath))
             {
@@ -360,35 +406,31 @@ namespace OpenRCT2::Ui
             return DialogType::none;
         }
 
-        static std::string GetKDialogFilterString(const std::vector<FileDialogDesc::Filter> filters)
+        static std::vector<std::string> GetKDialogFilterString(const std::vector<FileDialogDesc::Filter>& filters)
         {
-            std::stringstream filtersb;
-            bool first = true;
+            std::vector<std::string> filterStrings;
             for (const auto& filter : filters)
             {
-                if (!first)
-                {
-                    filtersb << "\\n";
-                }
-                first = false;
-
+                std::stringstream filtersb;
                 filtersb << filter.Name.c_str() << " (";
                 AddFilterCaseInsensitive(filtersb, filter.Pattern);
                 filtersb << ")";
+                filterStrings.push_back(filtersb.str());
             }
-            return filtersb.str();
+            return filterStrings;
         }
 
-        static std::string GetZenityFilterString(const std::vector<FileDialogDesc::Filter> filters)
+        static std::vector<std::string> GetZenityFilterString(const std::vector<FileDialogDesc::Filter>& filters)
         {
-            std::stringstream filtersb;
+            std::vector<std::string> filterStrings;
             for (const auto& filter : filters)
             {
-                filtersb << " --file-filter='" << filter.Name << " | ";
+                std::stringstream filtersb;
+                filtersb << "--file-filter=" << filter.Name << " | ";
                 AddFilterCaseInsensitive(filtersb, filter.Pattern);
-                filtersb << "'";
+                filterStrings.push_back(filtersb.str());
             }
-            return filtersb.str();
+            return filterStrings;
         }
 
         static void AddFilterCaseInsensitive(std::stringstream& stream, u8string pattern)
@@ -418,15 +460,6 @@ namespace OpenRCT2::Ui
             uiContext.ShowMessageBox(dialogMissingWarning);
             throw std::runtime_error(dialogMissingWarning);
         }
-
-        static std::string EscapePathForShell(std::string path)
-        {
-            for (size_t index = 0; (index = path.find('"', index)) != std::string::npos; index += 2)
-            {
-                path.replace(index, 1, "\\\"");
-            }
-            return '"' + path + '"';
-        }
     };
 
     std::unique_ptr<IPlatformUiContext> CreatePlatformUiContext()
diff --git a/src/openrct2/config/Config.cpp b/src/openrct2/config/Config.cpp
index 417113b643..b3dcc5d27b 100644
--- a/src/openrct2/config/Config.cpp
+++ b/src/openrct2/config/Config.cpp
@@ -807,10 +807,9 @@ namespace OpenRCT2::Config
             LOG_ERROR("Please install innoextract to extract files from GOG.");
             return false;
         }
-        int32_t exit_status = Platform::Execute(
-            String::stdFormat(
-                "%s '%s' --exclude-temp --output-dir '%s'", path.c_str(), installerPath.c_str(), targetPath.c_str()),
-            &output);
+        const char* args[] = { path.c_str(),   installerPath.c_str(), "--exclude-temp", "--silent",
+                               "--output-dir", targetPath.c_str(),    nullptr };
+        int32_t exit_status = Platform::Execute(args, &output);
         LOG_INFO("Exit status %d", exit_status);
         return exit_status == 0;
     }
diff --git a/src/openrct2/platform/Platform.Posix.cpp b/src/openrct2/platform/Platform.Posix.cpp
index dfeda0de99..5329756f19 100644
--- a/src/openrct2/platform/Platform.Posix.cpp
+++ b/src/openrct2/platform/Platform.Posix.cpp
@@ -29,6 +29,7 @@
     #include <pwd.h>
     #include <sys/stat.h>
     #include <sys/time.h>
+    #include <sys/wait.h>
     #include <unistd.h>
 
 // The name of the mutex used to prevent multiple instances of the game from running
@@ -113,55 +114,101 @@ namespace OpenRCT2::Platform
 
     bool FindApp(std::string_view app, std::string* output)
     {
-        return Execute(String::stdFormat("which %s 2> /dev/null", std::string(app).c_str()), output) == 0;
+        std::string appStr = std::string(app);
+        const char* args[] = { appStr.c_str(), "--version", nullptr };
+        int result = Execute(args, nullptr);
+        if (result == 0 && output)
+        {
+            *output = appStr;
+        }
+        return result == 0;
     }
 
-    int32_t Execute(std::string_view command, std::string* output)
+    int32_t Execute(const char* args[], std::string* output)
     {
-    #ifndef __EMSCRIPTEN__
-        LOG_VERBOSE("executing \"%s\"...", std::string(command).c_str());
-        FILE* fpipe = popen(std::string(command).c_str(), "r");
-        if (fpipe == nullptr)
+        // Build the command string from args for logging
+        std::string commandLine;
+        if (args && args[0])
         {
+            for (size_t i = 0; args[i]; ++i)
+            {
+                if (i > 0)
+                    commandLine += " ";
+                commandLine += args[i];
+            }
+        }
+    #ifndef __EMSCRIPTEN__
+        int status;
+        pid_t pid1;
+
+        LOG_INFO("Executing command: %s", commandLine.c_str());
+        int fd_pipe[2];
+        if (pipe(fd_pipe) != 0)
+        { /* create a pipe */
             return -1;
         }
-        if (output != nullptr)
-        {
-            // Read output into buffer
-            std::vector<char> outputBuffer;
-            char buffer[1024];
-            size_t readBytes;
-            while ((readBytes = fread(buffer, 1, sizeof(buffer), fpipe)) > 0)
+
+        pid1 = fork();
+        if (pid1 == 0)
+        {                      /* child process */
+            close(fd_pipe[0]); /* no reading from pipe */
+            /* write stdout in pipe */
+            if (dup2(fd_pipe[1], STDOUT_FILENO) == -1)
             {
-                outputBuffer.insert(outputBuffer.begin(), buffer, buffer + readBytes);
+                _exit(128);
             }
 
-            // Trim line breaks
-            size_t outputLength = outputBuffer.size();
-            for (size_t i = outputLength - 1; i != SIZE_MAX; i--)
-            {
-                if (outputBuffer[i] == '\n')
-                {
-                    outputLength = i;
-                }
-                else
-                {
-                    break;
-                }
-            }
-
-            // Convert to string
-            *output = std::string(outputBuffer.data(), outputLength);
+            /* const casting argv is fine:
+             * https://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html -> rational
+             */
+            execvp(args[0], const_cast<char**>(args));
+            _exit(129);
+        }
+        else if (pid1 < 0)
+        { /* fork() failed */
+            return -128;
         }
         else
-        {
-            fflush(fpipe);
-        }
+        {                      /* parent process */
+            close(fd_pipe[1]); /* no writing to the pipe */
+            if (waitpid(pid1, &status, 0) != pid1)
+            {
+                return -errno;
+            }
 
-        // Return exit code
-        return pclose(fpipe);
+            if (!WIFEXITED(status))
+            {
+                return -129;
+            }
+
+            if (WEXITSTATUS(status) >= 128)
+            {
+                return -130 - WEXITSTATUS(status);
+            }
+
+            // Optionally, read output from fd_pipe[0] if output != nullptr
+            if (output != nullptr)
+            {
+                std::vector<char> outputBuffer;
+                char buffer[1024];
+                ssize_t readBytes;
+                while ((readBytes = read(fd_pipe[0], buffer, sizeof(buffer))) > 0)
+                {
+                    outputBuffer.insert(outputBuffer.end(), buffer, buffer + readBytes);
+                }
+                // Trim line breaks
+                size_t outputLength = outputBuffer.size();
+                while (outputLength > 0 && outputBuffer[outputLength - 1] == '\n')
+                {
+                    --outputLength;
+                }
+                *output = std::string(outputBuffer.data(), outputLength);
+            }
+            close(fd_pipe[0]);
+            return 0; /* success! */
+        }
     #else
-        LOG_WARNING("Emscripten cannot execute processes. The commandline was '%s'.", std::string(command).c_str());
+        LOG_WARNING("Emscripten cannot execute processes. The commandline was '%s'.", commandLine.c_str());
         return -1;
     #endif // __EMSCRIPTEN__
     }
diff --git a/src/openrct2/platform/Platform.Win32.cpp b/src/openrct2/platform/Platform.Win32.cpp
index 8da9216b3b..47e835a15f 100644
--- a/src/openrct2/platform/Platform.Win32.cpp
+++ b/src/openrct2/platform/Platform.Win32.cpp
@@ -494,7 +494,7 @@ namespace OpenRCT2::Platform
         return false;
     }
 
-    int32_t Execute(std::string_view command, std::string* output)
+    int32_t Execute(const char* args[], std::string* output)
     {
         LOG_WARNING("Execute() not implemented for Windows!");
         return -1;
diff --git a/src/openrct2/platform/Platform.h b/src/openrct2/platform/Platform.h
index b2f3ccbdeb..00603ad076 100644
--- a/src/openrct2/platform/Platform.h
+++ b/src/openrct2/platform/Platform.h
@@ -92,7 +92,7 @@ namespace OpenRCT2::Platform
     RealWorldDate GetDateLocal();
 
     bool FindApp(std::string_view app, std::string* output);
-    int32_t Execute(std::string_view command, std::string* output = nullptr);
+    int32_t Execute(const char* args[], std::string* output = nullptr);
     bool ProcessIsElevated();
     float GetDefaultScale();