diff --git a/pcbnew/plugins/eagle/eagle_plugin.cpp b/pcbnew/plugins/eagle/eagle_plugin.cpp
index 0e3aabb364..d88736ad91 100644
--- a/pcbnew/plugins/eagle/eagle_plugin.cpp
+++ b/pcbnew/plugins/eagle/eagle_plugin.cpp
@@ -2920,7 +2920,7 @@ std::map<wxString, PCB_LAYER_ID> EAGLE_PLUGIN::DefaultLayerMappingCallback(
 }
 
 
-void EAGLE_PLUGIN::mapEagleLayersToKicad()
+void EAGLE_PLUGIN::mapEagleLayersToKicad( bool aIsLibraryCache )
 {
     std::vector<INPUT_LAYER_DESC> inputDescs;
 
@@ -2930,7 +2930,7 @@ void EAGLE_PLUGIN::mapEagleLayersToKicad()
 
         INPUT_LAYER_DESC layerDesc;
         std::tie( layerDesc.AutoMapLayer, layerDesc.PermittedLayers, layerDesc.Required ) =
-                defaultKicadLayer( eLayer.number );
+                defaultKicadLayer( eLayer.number, aIsLibraryCache );
 
         if( layerDesc.AutoMapLayer == UNDEFINED_LAYER )
             continue; // Ignore unused copper layers
@@ -2957,7 +2957,8 @@ PCB_LAYER_ID EAGLE_PLUGIN::kicad_layer( int aEagleLayer ) const
 }
 
 
-std::tuple<PCB_LAYER_ID, LSET, bool> EAGLE_PLUGIN::defaultKicadLayer( int aEagleLayer ) const
+std::tuple<PCB_LAYER_ID, LSET, bool> EAGLE_PLUGIN::defaultKicadLayer( int aEagleLayer,
+                                                                      bool aIsLibraryCache ) const
 {
     // eagle copper layer:
     if( aEagleLayer >= 1 && aEagleLayer < int( arrayDim( m_cu_map ) ) )
@@ -3078,7 +3079,19 @@ std::tuple<PCB_LAYER_ID, LSET, bool> EAGLE_PLUGIN::defaultKicadLayer( int aEagle
     case EAGLE_LAYER::BTEST:
     case EAGLE_LAYER::HOLES:
     default:
-        kiLayer = UNDEFINED_LAYER;
+        if( aIsLibraryCache )
+        {
+            if( aEagleLayer != EAGLE_LAYER::MILLING && aEagleLayer != EAGLE_LAYER::TTEST &&
+                aEagleLayer != EAGLE_LAYER::BTEST && aEagleLayer != EAGLE_LAYER::HOLES )
+                kiLayer = Dwgs_User;
+            else
+                kiLayer = UNDEFINED_LAYER;
+        }
+        else
+        {
+            kiLayer = UNSELECTED_LAYER;
+        }
+
         break;
     }
 
@@ -3191,7 +3204,7 @@ void EAGLE_PLUGIN::cacheLib( const wxString& aLibPath )
             m_xpath->push( "eagle.drawing.layers" );
             wxXmlNode* layers  = drawingChildren["layers"];
             loadLayerDefs( layers );
-            mapEagleLayersToKicad();
+            mapEagleLayersToKicad( true );
             m_xpath->pop();
 
             m_xpath->push( "eagle.drawing.library" );
diff --git a/pcbnew/plugins/eagle/eagle_plugin.h b/pcbnew/plugins/eagle/eagle_plugin.h
index 5e310e4320..fc5a87b26d 100644
--- a/pcbnew/plugins/eagle/eagle_plugin.h
+++ b/pcbnew/plugins/eagle/eagle_plugin.h
@@ -191,15 +191,40 @@ private:
     /// create a font size (fontz) from an eagle font size scalar and KiCad font thickness
     wxSize  kicad_fontz( const ECOORD& d, int aTextThickness ) const;
 
-    /// Generate mapping between Eagle na KiCad layers
-    void mapEagleLayersToKicad();
+    /**
+     * Generate mapping between Eagle and KiCad layers.
+     *
+     * @warning It is imperative that this gets called correctly because footprint libraries
+     *          do not get remapped by the user on load.  Otherwise, Pcbnew will crash when
+     *          attempting to load footprint libraries that contain layers that do not exist
+     *          in the #EAGLE_LAYER definitions.
+     *
+     * @param aIsLibraryCache is the flag to indicate when mapping the footprint library cache
+     *                        layers rather than the board layers.
+     */
+    void mapEagleLayersToKicad( bool aIsLibraryCache = false );
 
     /// Convert an Eagle layer to a KiCad layer.
     PCB_LAYER_ID kicad_layer( int aLayer ) const;
 
-    /// Get default KiCad layer corresponding to an Eagle layer of the board,
-    /// a set of sensible layer mapping options and required flag
-    std::tuple<PCB_LAYER_ID, LSET, bool> defaultKicadLayer( int aEagleLayer ) const;
+    /**
+     * Get the default KiCad layer corresponding to an Eagle layer of the board,
+     * a set of sensible layer mapping options and required flag
+     *
+     * @note The Eagle MILLING, TTEST, BTEST, and HOLES layers are set to #UNDEFINED_LAYER
+     *       for historical purposes.  All other Eagle layers that do not directly map to
+     *       KiCad layers will be set to the #Dwg_User layer when loading Eagle footprint
+     *       libraries to prevent data loss.
+     *
+     * @see #EAGLE_LAYER and defaultKiCadLayer().
+     *
+     * @param aEagleLayer is the Eagle layer to map.
+     * @param aIsLibraryCache is a flag to indicate if the mapping is for board or footprint
+     *                        library cache objects.
+     * @return a tuple containing the mapped layer.
+     */
+    std::tuple<PCB_LAYER_ID, LSET, bool> defaultKicadLayer( int aEagleLayer,
+                                                            bool aIsLibraryCache = false ) const;
 
     /// Get Eagle layer name by its number
     const wxString& eagle_layer_name( int aLayer ) const;