diff --git a/backends/imgui_impl_sdl2.cpp b/backends/imgui_impl_sdl2.cpp
index f578977c4..ebad76010 100644
--- a/backends/imgui_impl_sdl2.cpp
+++ b/backends/imgui_impl_sdl2.cpp
@@ -21,6 +21,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2026-04-16: Made ImGui_ImplSDL2_GetContentScaleForWindow(), ImGui_ImplSDL2_GetContentScaleForDisplay() helpers return a minimum of 1.0f, as some Linux setup seems to report <1.0f value and this breaks scaling border size. (#9369)
 //  2026-02-13: Inputs: systems other than X11 are back to starting mouse capture on mouse down (reverts 2025-02-26 change). Only X11 requires waiting for a drag by default (not ideal, but a better default for X11 users). Added ImGui_ImplSDL2_SetMouseCaptureMode() for X11 debugger users. (#3650, #6410, #9235)
 //  2026-01-15: Changed GetClipboardText() handler to return nullptr on error aka clipboard contents is not text. Consistent with other backends. (#9168)
 //  2025-09-24: Skip using the SDL_GetGlobalMouseState() state when one of our window is hovered, as the SDL_MOUSEMOTION data is reliable. Fix macOS notch mouse coordinates issue in fullscreen mode + better perf on X11. (#7919, #7786)
@@ -748,6 +749,7 @@ float ImGui_ImplSDL2_GetContentScaleForWindow(SDL_Window* window)
     return ImGui_ImplSDL2_GetContentScaleForDisplay(SDL_GetWindowDisplayIndex(window));
 }
 
+// SDL_GetDisplayDPI() seems rather unreliable on Linux.
 float ImGui_ImplSDL2_GetContentScaleForDisplay(int display_index)
 {
     const char* sdl_driver = SDL_GetCurrentVideoDriver();
@@ -757,7 +759,11 @@ float ImGui_ImplSDL2_GetContentScaleForDisplay(int display_index)
 #if !defined(__APPLE__) && !defined(__EMSCRIPTEN__) && !defined(__ANDROID__)
     float dpi = 0.0f;
     if (SDL_GetDisplayDPI(display_index, &dpi, nullptr, nullptr) == 0)
+    {
+        if (dpi < 96.0f)
+            dpi = 96.0f;
         return dpi / 96.0f;
+    }
 #endif
 #endif
     IM_UNUSED(display_index);
diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt
index 05dd294e1..baabbcbc0 100644
--- a/docs/CHANGELOG.txt
+++ b/docs/CHANGELOG.txt
@@ -93,6 +93,9 @@ Other Changes:
     to validation issue. (#9343) [@Hunam6]
   - Metal: use a dedicated `bufferCacheLock` to avoid crashing when `bufferCache` is
     replaced by a new object while being used for `@synchronize()`. (#9367) [@andygrundman]
+  - SDL2: made `ImGui_ImplSDL2_GetContentScaleForWindow()`/`ImGui_ImplSDL2_GetContentScaleForDisplay()`
+    helpers return a minimum of 1.0f, as some Linux setup seems to report <1.0f value
+    and this breaks scaling border size. (#9369)
 
 
 -----------------------------------------------------------------------
diff --git a/imgui.cpp b/imgui.cpp
index 79e9a7808..66a4a18d2 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -1542,6 +1542,7 @@ ImGuiStyle::ImGuiStyle()
 
 
 // Scale all spacing/padding/thickness values. Do not scale fonts.
+// Consider not calling this if your initial scale factor if <1.0.
 // Important: This operation is lossy because we round all sizes to integer. If you need to change your scale multiples, call this over a freshly initialized ImGuiStyle structure rather than scaling multiple times.
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {