diff --git a/ligature/OperatorMonoSSmLig-Book/config.xml b/ligature/OperatorMonoSSmLig-Book/config.xml
index 5bd3c9f..d8bbd95 100644
--- a/ligature/OperatorMonoSSmLig-Book/config.xml
+++ b/ligature/OperatorMonoSSmLig-Book/config.xml
@@ -102,7 +102,7 @@
         <metricDataFormat value="0"/>
         
     
-        <numberOfHMetrics value="481"/>
+        <numberOfHMetrics value="482"/>
         
   
     </hhea>
diff --git a/ligature/OperatorMonoSSmLig-Book/glyphs/underscore_underscore.liga.xml b/ligature/OperatorMonoSSmLig-Book/glyphs/underscore_underscore.liga.xml
new file mode 100644
index 0000000..5261bc2
--- /dev/null
+++ b/ligature/OperatorMonoSSmLig-Book/glyphs/underscore_underscore.liga.xml
@@ -0,0 +1,11 @@
+<Glyph name="underscore_underscore.liga" lsb="-629" width="625">
+    <CharString>
+        -129 73 hstem
+        -629 1258 vstem
+        629 -56 rmoveto
+        -1258 -73 1258 hlineto
+        endchar
+    </CharString>
+    <Subrs/>
+    <GlobalSubrs/>
+</Glyph>
\ No newline at end of file
diff --git a/ligature/OperatorMonoSSmLig-BookItalic/config.xml b/ligature/OperatorMonoSSmLig-BookItalic/config.xml
index 0fb6432..01f1af5 100644
--- a/ligature/OperatorMonoSSmLig-BookItalic/config.xml
+++ b/ligature/OperatorMonoSSmLig-BookItalic/config.xml
@@ -102,7 +102,7 @@
         <metricDataFormat value="0"/>
         
     
-        <numberOfHMetrics value="478"/>
+        <numberOfHMetrics value="479"/>
         
   
     </hhea>
diff --git a/ligature/OperatorMonoSSmLig-BookItalic/glyphs/underscore_underscore.liga.xml b/ligature/OperatorMonoSSmLig-BookItalic/glyphs/underscore_underscore.liga.xml
new file mode 100644
index 0000000..58ad4e6
--- /dev/null
+++ b/ligature/OperatorMonoSSmLig-BookItalic/glyphs/underscore_underscore.liga.xml
@@ -0,0 +1,13 @@
+<Glyph name="underscore_underscore.liga" lsb="-697" width="625">
+    <CharString>
+        -126 70 hstem
+        -697 1271 vstem
+        574 -56 rmoveto
+        -1257 hlineto
+        -14 -70 rlineto
+        1258 hlineto
+        endchar
+    </CharString>
+    <Subrs/>
+    <GlobalSubrs/>
+</Glyph>
\ No newline at end of file