diff --git a/specs/udmf_zdoom.txt b/specs/udmf_zdoom.txt
index 835f3780e..3499500ee 100644
--- a/specs/udmf_zdoom.txt
+++ b/specs/udmf_zdoom.txt
@@ -214,6 +214,9 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       damagehazard = <bool>;          // Changes damage model to Strife's delayed damage for the given sector. Default = false.
       floorterrain = <string>;        // Sets the terrain for the sector's floor. Default = 'use the flat texture's terrain definition.'
       ceilingterrain = <string>;      // Sets the terrain for the sector's ceiling. Default = 'use the flat texture's terrain definition.'
+	  
+	  floor_reflect = <float>;        // reflectiveness of floor (OpenGL only, not functional on sloped sectors)
+	  ceiling_reflect = <float>;      // reflectiveness of ceiling (OpenGL only, not functional on sloped sectors)
 
       portal_ceil_alpha = <float>     // translucency of ceiling portal (default is 0 (not visible))
       portal_ceil_blocksound = <bool> // ceiling portal blocks sound.
@@ -406,6 +409,9 @@ Added 'moreids' for linedefs and sectors.
 added clarification about character encoding
 added sector damage properties.
 
+1.27 05.01.2016
+floor_reflect and ceiling_reflect.
+
 ===============================================================================
 EOF
 ===============================================================================
diff --git a/src/namedef.h b/src/namedef.h
index 62d513437..61d7303a4 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -575,6 +575,8 @@ xx(damageterraineffect)
 xx(damagehazard)
 xx(floorterrain)
 xx(ceilingterrain)
+xx(floor_reflect)
+xx(ceiling_reflect)
 
 // USDF keywords
 xx(Amount)
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index d3bcc742d..43d1833af 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -4080,6 +4080,13 @@ void P_SetupLevel (const char *lumpname, int position)
 	// set up world state
 	P_SpawnSpecials ();
 
+	// disable reflective planes on sloped sectors.
+	for (auto i = 0; i < numsectors; i++)
+	{
+		if (sectors[i].floorplane.isSlope()) sectors[i].reflect[sector_t::floor] = 0;
+		if (sectors[i].ceilingplane.isSlope()) sectors[i].reflect[sector_t::ceiling] = 0;
+	}
+
 	// This must be done BEFORE the PolyObj Spawn!!!
 	Renderer->PreprocessLevel();
 
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 2ef8a9ced..15d1b48d3 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -1563,6 +1563,14 @@ public:
 					sec->terrainnum[sector_t::ceiling] = P_FindTerrain(CheckString(key));
 					break;
 
+				case NAME_floor_reflect:
+					sec->reflect[sector_t::floor] = (float)CheckFloat(key);
+					break;
+
+				case NAME_ceiling_reflect:
+					sec->reflect[sector_t::ceiling] = (float)CheckFloat(key);
+					break;
+
 				case NAME_MoreIds:
 					// delay parsing of the tag string until parsing of the sector is complete
 					// This ensures that the ID is always the first tag in the list.