--- /dev/null
+++ b/src/api/wayfire/output-transform.hpp
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <array>
+#include <optional>
+#include <string_view>
+#include <wayland-server-protocol.h>
+
+namespace wf
+{
+// Canonical configuration names, in wl_output_transform enum order. Keep the
+// earlier WCM spellings readable so saved profiles continue to work.
+inline constexpr std::array<std::string_view, 8> output_transform_names = {
+    "normal", "90", "180", "270", "flipped", "90_flipped", "180_flipped", "270_flipped",
+};
+
+inline std::optional<wl_output_transform> parse_output_transform(std::string_view name)
+{
+    for (size_t i = 0; i < output_transform_names.size(); ++i)
+    {
+        if (name == output_transform_names[i]) return static_cast<wl_output_transform>(i);
+    }
+
+    if (name == "flipped-90") return WL_OUTPUT_TRANSFORM_FLIPPED_90;
+    if (name == "flipped-180") return WL_OUTPUT_TRANSFORM_FLIPPED_180;
+    if (name == "flipped-270") return WL_OUTPUT_TRANSFORM_FLIPPED_270;
+    return std::nullopt;
+}
+}
--- a/src/core/output-layout.cpp
+++ b/src/core/output-layout.cpp
@@ -1,3 +1,4 @@
+#include <wayfire/output-transform.hpp>
 #include <wayfire/window-scope.hpp>
 #include <wayfire/workspace-set.hpp>
 #include "wayfire/output.hpp"
@@ -92,25 +93,9 @@
 };
 }
 
-static std::map<std::string, wl_output_transform> output_transforms = {
-    {"normal", WL_OUTPUT_TRANSFORM_NORMAL},
-    {"90", WL_OUTPUT_TRANSFORM_90},
-    {"180", WL_OUTPUT_TRANSFORM_180},
-    {"270", WL_OUTPUT_TRANSFORM_270},
-    {"flipped", WL_OUTPUT_TRANSFORM_FLIPPED},
-    {"90_flipped", WL_OUTPUT_TRANSFORM_FLIPPED_90},
-    {"180_flipped", WL_OUTPUT_TRANSFORM_FLIPPED_180},
-    {"270_flipped", WL_OUTPUT_TRANSFORM_FLIPPED_270},
-};
-
 wl_output_transform wf::layout_detail::get_transform_from_string(std::string_view transform)
 {
-    auto it = output_transforms.find(std::string{transform});
-    if (it != output_transforms.end())
-    {
-        return it->second;
-    }
-
+    if (auto parsed = wf::parse_output_transform(transform)) return *parsed;
     LOGE("Bad output transform in config: ", transform);
     return WL_OUTPUT_TRANSFORM_NORMAL;
 }
@@ -127,13 +112,8 @@
 
 std::string wf::layout_detail::wl_transform_to_string(wl_output_transform transform)
 {
-    for (auto& it : output_transforms)
-    {
-        if (it.second == transform)
-        {
-            return it.first;
-        }
-    }
+    if (static_cast<size_t>(transform) < wf::output_transform_names.size())
+        return std::string(wf::output_transform_names[transform]);
 
     return "normal";
 }
--- a/plugins/single_plugins/output-control.cpp
+++ b/plugins/single_plugins/output-control.cpp
@@ -1,3 +1,4 @@
+#include <wayfire/output-transform.hpp>
 #include <wayfire/window-scope.hpp>
 // Display settings transactions for WCM. The compositor owns the timeout;
 // unconfirmed settings are never written to disk.
@@ -324,13 +325,9 @@
             state.position = *wf::option_type::from_string<wf::output_config::position_t>(value(changes, pre + "position"));
             state.scale = std::stod(value(changes, pre + "scale"));
             if (!std::isfinite(state.scale) || state.scale < .25 || state.scale > 8) throw std::runtime_error("Scale must be between 0.25 and 8");
-            const std::map<std::string, wl_output_transform> transforms = {{"normal", WL_OUTPUT_TRANSFORM_NORMAL},
-                {"90", WL_OUTPUT_TRANSFORM_90}, {"180", WL_OUTPUT_TRANSFORM_180}, {"270", WL_OUTPUT_TRANSFORM_270},
-                {"flipped", WL_OUTPUT_TRANSFORM_FLIPPED}, {"flipped-90", WL_OUTPUT_TRANSFORM_FLIPPED_90},
-                {"flipped-180", WL_OUTPUT_TRANSFORM_FLIPPED_180}, {"flipped-270", WL_OUTPUT_TRANSFORM_FLIPPED_270}};
-            auto t = transforms.find(value(changes, pre + "transform"));
-            if (t == transforms.end()) throw std::runtime_error("Unknown transform for " + name);
-            state.transform = t->second;
+            auto transform = wf::parse_output_transform(value(changes, pre + "transform"));
+            if (!transform) throw std::runtime_error("Unknown transform for " + name);
+            state.transform = *transform;
             state.vrr = value(changes, pre + "vrr") == "true";
             state.hdr = value(changes, pre + "hdr") == "true";
             state.depth = std::stoi(value(changes, pre + "depth"));
@@ -432,6 +429,8 @@
             if (!now.count(head) || (state.source != wf::OUTPUT_IMAGE_SOURCE_NONE &&
                 (head->width != state.mode.width || head->height != state.mode.height || std::abs(head->refresh - state.mode.refresh) > 500)))
                 throw std::runtime_error("A monitor did not accept the requested mode; reverted");
+            if (state.source != wf::OUTPUT_IMAGE_SOURCE_NONE && head->transform != state.transform)
+                throw std::runtime_error("A monitor did not accept the requested rotation; reverted");
         }
         auto wanted_members = members(requested);
         auto virtual_output = wf::get_core().output_layout->find_output("VIRTUAL-1");