diff --git a/src/gl/dynlights/gl_dynlight1.cpp b/src/gl/dynlights/gl_dynlight1.cpp
index c41290740..42f1c27cf 100644
--- a/src/gl/dynlights/gl_dynlight1.cpp
+++ b/src/gl/dynlights/gl_dynlight1.cpp
@@ -141,10 +141,10 @@ void gl_AddLightToList(int group, ADynamicLight * light, FDynLightData &ldata)
 		spotOuterAngle = light->SpotOuterAngle.Cos();
 
 		DAngle negPitch = -light->Angles.Pitch;
-		float xyLen = negPitch.Cos();
-		spotDirX = -light->Angles.Yaw.Cos() * xyLen;
-		spotDirY = -light->Angles.Yaw.Sin() * xyLen;
-		spotDirZ = -negPitch.Sin();
+		double xzLen = negPitch.Cos();
+		spotDirX = -light->Angles.Yaw.Cos() * xzLen;
+		spotDirY = -negPitch.Sin();
+		spotDirZ = -light->Angles.Yaw.Sin() * xzLen;
 	}
 
 	float *data = &ldata.arrays[i][ldata.arrays[i].Reserve(16)];
diff --git a/src/gl/scene/gl_spritelight.cpp b/src/gl/scene/gl_spritelight.cpp
index 2d2e65b76..bde9f1450 100644
--- a/src/gl/scene/gl_spritelight.cpp
+++ b/src/gl/scene/gl_spritelight.cpp
@@ -49,6 +49,13 @@
 FDynLightData modellightdata;
 int modellightindex = -1;
 
+template<class T>
+T smoothstep(const T edge0, const T edge1, const T x)
+{
+	auto t = clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
+	return t * t * (3.0 - 2.0 * t);
+}
+
 //==========================================================================
 //
 // Sets a single light value from all dynamic lights affecting the specified location
@@ -70,6 +77,7 @@ void gl_SetDynSpriteLight(AActor *self, float x, float y, float z, subsector_t *
 		if (light->visibletoplayer && !(light->flags2&MF2_DORMANT) && (!(light->lightflags&LF_DONTLIGHTSELF) || light->target != self) && !(light->lightflags&LF_DONTLIGHTACTORS))
 		{
 			float dist;
+			FVector3 L;
 
 			// This is a performance critical section of code where we cannot afford to let the compiler decide whether to inline the function or not.
 			// This will do the calculations explicitly rather than calling one of AActor's utility functions.
@@ -80,14 +88,15 @@ void gl_SetDynSpriteLight(AActor *self, float x, float y, float z, subsector_t *
 				if (fromgroup == togroup || fromgroup == 0 || togroup == 0) goto direct;
 
 				DVector2 offset = Displacements.getOffset(fromgroup, togroup);
-				dist = FVector3(x - light->X() - offset.X, y - light->Y() - offset.Y, z - light->Z()).LengthSquared();
+				L = FVector3(x - light->X() - offset.X, y - light->Y() - offset.Y, z - light->Z());
 			}
 			else
 			{
 			direct:
-				dist = FVector3(x - light->X(), y - light->Y(), z - light->Z()).LengthSquared();
+				L = FVector3(x - light->X(), y - light->Y(), z - light->Z());
 			}
 
+			dist = L.LengthSquared();
 			radius = light->GetRadius();
 
 			if (dist < radius * radius)
@@ -96,6 +105,17 @@ void gl_SetDynSpriteLight(AActor *self, float x, float y, float z, subsector_t *
 
 				frac = 1.0f - (dist / radius);
 
+				if (light->IsSpot())
+				{
+					DAngle negPitch = -light->Angles.Pitch;
+					double xzLen = negPitch.Cos();
+					double spotDirX = -light->Angles.Yaw.Cos() * xzLen;
+					double spotDirY = -negPitch.Sin();
+					double spotDirZ = -light->Angles.Yaw.Sin() * xzLen;
+					double cosDir = L.X * spotDirX + L.Y * spotDirY + L.Z * spotDirZ;
+					frac *= (float)smoothstep(light->SpotOuterAngle.Cos(), light->SpotInnerAngle.Cos(), cosDir);
+				}
+
 				if (frac > 0 && GLRenderer->mShadowMap.ShadowTest(light, { x, y, z }))
 				{
 					lr = light->GetRed() / 255.0f;