diff --git a/sdf/1.2/visual.sdf b/sdf/1.2/visual.sdf
index 6b4913260..550fe4448 100644
--- a/sdf/1.2/visual.sdf
+++ b/sdf/1.2/visual.sdf
@@ -41,7 +41,7 @@
       <description></description>
 
       <attribute name="type" type="string" default="pixel" required="1">
-        <description>vertex, pixel, normal_map_objectspace, normal_map_tangentspace</description>
+        <description>vertex, pixel, normal_map_object_space, normal_map_tangent_space</description>
       </attribute>
 
       <element name="normal_map" type="string" default="__default__" required="0">
diff --git a/sdf/1.3/visual.sdf b/sdf/1.3/visual.sdf
index 029ef22bd..10dfb3a56 100644
--- a/sdf/1.3/visual.sdf
+++ b/sdf/1.3/visual.sdf
@@ -41,7 +41,7 @@
       <description></description>
 
       <attribute name="type" type="string" default="pixel" required="1">
-        <description>vertex, pixel, normal_map_objectspace, normal_map_tangentspace</description>
+        <description>vertex, pixel, normal_map_object_space, normal_map_tangent_space</description>
       </attribute>
 
       <element name="normal_map" type="string" default="__default__" required="0">
diff --git a/sdf/1.4/visual.sdf b/sdf/1.4/visual.sdf
index 644bff44a..f8043dfca 100644
--- a/sdf/1.4/visual.sdf
+++ b/sdf/1.4/visual.sdf
@@ -41,7 +41,7 @@
       <description></description>
 
       <attribute name="type" type="string" default="pixel" required="1">
-        <description>vertex, pixel, normal_map_objectspace, normal_map_tangentspace</description>
+        <description>vertex, pixel, normal_map_object_space, normal_map_tangent_space</description>
       </attribute>
 
       <element name="normal_map" type="string" default="__default__" required="0">
diff --git a/sdf/1.5/material.sdf b/sdf/1.5/material.sdf
index 137436eea..fdf5fa6a7 100644
--- a/sdf/1.5/material.sdf
+++ b/sdf/1.5/material.sdf
@@ -17,7 +17,7 @@
   <element name="shader" required="0">
 
     <attribute name="type" type="string" default="pixel" required="1">
-      <description>vertex, pixel, normal_map_objectspace, normal_map_tangentspace</description>
+      <description>vertex, pixel, normal_map_object_space, normal_map_tangent_space</description>
     </attribute>
 
     <element name="normal_map" type="string" default="__default__" required="0">
diff --git a/sdf/1.6/material.sdf b/sdf/1.6/material.sdf
index f17690759..7cd011598 100644
--- a/sdf/1.6/material.sdf
+++ b/sdf/1.6/material.sdf
@@ -17,7 +17,7 @@
   <element name="shader" required="0">
 
     <attribute name="type" type="string" default="pixel" required="1">
-      <description>vertex, pixel, normal_map_objectspace, normal_map_tangentspace</description>
+      <description>vertex, pixel, normal_map_object_space, normal_map_tangent_space</description>
     </attribute>
 
     <element name="normal_map" type="string" default="__default__" required="0">
diff --git a/src/Material.cc b/src/Material.cc
index 84ed3a1e0..722487afd 100644
--- a/src/Material.cc
+++ b/src/Material.cc
@@ -176,8 +176,12 @@ Errors Material::Load(sdf::ElementPtr _sdf)
       this->dataPtr->shader = ShaderType::VERTEX;
     else if (typePair.first == "normal_map_objectspace")
       this->dataPtr->shader = ShaderType::NORMAL_MAP_OBJECTSPACE;
+    else if (typePair.first == "normal_map_object_space")
+      this->dataPtr->shader = ShaderType::NORMAL_MAP_OBJECTSPACE;
     else if (typePair.first == "normal_map_tangentspace")
       this->dataPtr->shader = ShaderType::NORMAL_MAP_TANGENTSPACE;
+    else if (typePair.first == "normal_map_tangent_space")
+      this->dataPtr->shader = ShaderType::NORMAL_MAP_TANGENTSPACE;
     else
     {
       errors.push_back({ErrorCode::ELEMENT_INVALID,
diff --git a/test/sdf/material.sdf b/test/sdf/material.sdf
index 5869f6de4..5b1c2e68f 100644
--- a/test/sdf/material.sdf
+++ b/test/sdf/material.sdf
@@ -26,7 +26,7 @@
 
       <visual name="visual3">
         <material>
-          <shader type="normal_map_objectspace">
+          <shader type="normal_map_object_space">
             <normal_map>my_normal_map</normal_map>
           </shader>
         </material>
diff --git a/test/sdf/material_normal_map_missing.sdf b/test/sdf/material_normal_map_missing.sdf
index 033efffb4..08607c335 100644
--- a/test/sdf/material_normal_map_missing.sdf
+++ b/test/sdf/material_normal_map_missing.sdf
@@ -4,7 +4,7 @@
     <link name="link">
       <visual name="visual1">
         <material>
-          <shader type="normal_map_tangentspace">
+          <shader type="normal_map_tangent_space">
           </shader>
         </material>
       </visual>