diff --git a/common/lset.cpp b/common/lset.cpp
index ec82da8523..a6d0e937ae 100644
--- a/common/lset.cpp
+++ b/common/lset.cpp
@@ -45,7 +45,10 @@ LSET::LSET( std::initializer_list<PCB_LAYER_ID> aList ) :
     LSET()
 {
     for( PCB_LAYER_ID layer : aList )
-        set( layer );
+    {
+        if( layer > 0 )
+            set( layer );
+    }
 }
 
 
@@ -53,14 +56,20 @@ LSET::LSET( const LSEQ& aSeq ) :
     LSET()
 {
     for( PCB_LAYER_ID layer : aSeq )
-        set( layer );
+    {
+        if( layer > 0 )
+            set( layer );
+    }
 }
 
 
 LSET::LSET( const LAYER_RANGE& aRange )
 {
     for( PCB_LAYER_ID layer : aRange )
-        set( layer );
+    {
+        if( layer > 0 )
+            set( layer );
+    }
 }
 
 
@@ -966,4 +975,4 @@ LSET::non_copper_layers_iterator LSET::non_copper_layers_end() const
 }
 
 
-#endif
\ No newline at end of file
+#endif
diff --git a/include/lset.h b/include/lset.h
index cc62b1a338..02f348e71b 100644
--- a/include/lset.h
+++ b/include/lset.h
@@ -59,6 +59,10 @@ public:
      */
     bool Contains( PCB_LAYER_ID aLayer )
     {
+        // At the moment, LSET cannot store negative layers, but PCB_LAYER_ID can contain them
+        if( aLayer < 0 )
+           return false;
+
         try
         {
             return test( aLayer );