diff --git a/imgui.h b/imgui.h
index fb30f3624..d9f6a8cd1 100644
--- a/imgui.h
+++ b/imgui.h
@@ -2335,7 +2335,7 @@ struct ImGuiStyle
     ImGuiDir    ColorButtonPosition;        // Side of the color button in the ColorEdit4 widget (left/right). Defaults to ImGuiDir_Right.
     ImVec2      ButtonTextAlign;            // Alignment of button text when button is larger than text. Defaults to (0.5f, 0.5f) (centered).
     ImVec2      SelectableTextAlign;        // Alignment of selectable text. Defaults to (0.0f, 0.0f) (top-left aligned). It's generally important to keep this left-aligned if you want to lay multiple items on a same line.
-    float       SeparatorSize;              // Thickness of border in Separator()
+    float       SeparatorSize;              // Thickness of border in Separator(). Must be >= 1.0f.
     float       SeparatorTextBorderSize;    // Thickness of border in SeparatorText()
     ImVec2      SeparatorTextAlign;         // Alignment of text within the separator. Defaults to (0.0f, 0.5f) (left aligned, center).
     ImVec2      SeparatorTextPadding;       // Horizontal offset of text from each edge of the separator + spacing on other axis. Generally small values. .y is recommended to be == FramePadding.y.
@@ -2365,7 +2365,7 @@ struct ImGuiStyle
 
     // Functions
     IMGUI_API   ImGuiStyle();
-    IMGUI_API   void ScaleAllSizes(float scale_factor); // Scale all spacing/padding/thickness values. Do not scale fonts.
+    IMGUI_API   void ScaleAllSizes(float scale_factor); // Scale all spacing/padding/thickness values. Do not scale fonts. See comments in definition. Consider not calling this if your initial scale factor if <1.0.
 
     // Obsolete names
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
diff --git a/imgui_widgets.cpp b/imgui_widgets.cpp
index f5b7e49fe..50fec659d 100644
--- a/imgui_widgets.cpp
+++ b/imgui_widgets.cpp
@@ -1728,7 +1728,7 @@ void ImGui::Separator()
     if (window->DC.CurrentColumns)
         flags |= ImGuiSeparatorFlags_SpanAllColumns;
 
-    SeparatorEx(flags, g.Style.SeparatorSize);
+    SeparatorEx(flags, ImMax(g.Style.SeparatorSize, 1.0f));
 }
 
 void ImGui::SeparatorTextEx(ImGuiID id, const char* label, const char* label_end, float extra_w)