diff --git a/worldedit-core/src/main/java/com/fastasyncworldedit/core/extension/factory/parser/mask/SurfaceAngleMaskParser.java b/worldedit-core/src/main/java/com/fastasyncworldedit/core/extension/factory/parser/mask/SurfaceAngleMaskParser.java
new file mode 100644
index 000000000..ab011f412
--- /dev/null
+++ b/worldedit-core/src/main/java/com/fastasyncworldedit/core/extension/factory/parser/mask/SurfaceAngleMaskParser.java
@@ -0,0 +1,45 @@
+package com.fastasyncworldedit.core.extension.factory.parser.mask;
+
+import com.fastasyncworldedit.core.extension.factory.parser.RichParser;
+import com.fastasyncworldedit.core.function.mask.SurfaceAngleMask;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.command.util.SuggestionHelper;
+import com.sk89q.worldedit.extension.input.InputParseException;
+import com.sk89q.worldedit.extension.input.ParserContext;
+import com.sk89q.worldedit.function.mask.Mask;
+
+import javax.annotation.Nonnull;
+import java.util.stream.Stream;
+
+public class SurfaceAngleMaskParser extends RichParser<Mask> {
+
+    /**
+     * Create a new surface angle mask parser with a defined prefix for the result, e.g. {@code #simplex}.
+     *
+     * @param worldEdit the worldedit instance.
+     */
+    public SurfaceAngleMaskParser(WorldEdit worldEdit) {
+        super(worldEdit, "#surfaceangle");
+    }
+
+    @Override
+    protected Stream<String> getSuggestions(String argumentInput, int index) {
+        if (index <= 2) {
+            return SuggestionHelper.suggestPositiveDoubles(argumentInput);
+        }
+        return Stream.empty();
+    }
+
+    public Mask parseFromInput(@Nonnull String[] arguments, ParserContext context) throws InputParseException {
+        if (arguments.length > 3) {
+            return null;
+        }
+
+        double min = Double.parseDouble(arguments[0]);
+        double max = Double.parseDouble(arguments[1]);
+
+        int size = (arguments.length > 2 ? Integer.parseInt(arguments[2]) : 1);
+        return new SurfaceAngleMask(context.getExtent(), min, max, size);
+    }
+
+}
diff --git a/worldedit-core/src/main/java/com/fastasyncworldedit/core/function/mask/SurfaceAngleMask.java b/worldedit-core/src/main/java/com/fastasyncworldedit/core/function/mask/SurfaceAngleMask.java
new file mode 100644
index 000000000..ce42a2d7e
--- /dev/null
+++ b/worldedit-core/src/main/java/com/fastasyncworldedit/core/function/mask/SurfaceAngleMask.java
@@ -0,0 +1,101 @@
+package com.fastasyncworldedit.core.function.mask;
+
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.function.mask.AbstractExtentMask;
+import com.sk89q.worldedit.function.mask.Mask;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.math.Vector3;
+
+import java.util.ArrayList;
+
+public class SurfaceAngleMask extends AbstractExtentMask {
+
+    private final double min;
+    private final double max;
+    private final int size;
+
+    public SurfaceAngleMask(Extent extent, double min, double max, int size) {
+        super(extent);
+        this.min = min;
+        this.max = max;
+        this.size = size;
+    }
+
+    @Override
+    public boolean test(BlockVector3 vector) {
+        if (!vector.getBlock(getExtent()).isAir() && nextToAir(vector)) {
+            double angle = 1 - getAverageAirDirection(vector.toVector3(), size).getY();
+            return (angle >= (min / 90.0) && angle <= (max / 90.0));
+        }
+        return false;
+    }
+
+    @Override
+    public boolean test(Extent extent, BlockVector3 vector) {
+        if (!vector.getBlock(getExtent()).isAir() && nextToAir(vector)) {
+            double angle = 1 - getAverageAirDirection(vector.toVector3(), size).getY();
+            return (angle >= (min / 90.0) && angle <= (max / 90.0));
+        }
+        return false;
+    }
+
+    private Vector3 getAverageAirDirection(Vector3 currentLocation, int size) {
+        ArrayList<Vector3> airDirections = new ArrayList<>();
+        for (int i = -size; i <= size; i++) {
+            for (int j = -size; j <= size; j++) {
+                for (int k = -size; k <= size; k++) {
+                    Vector3 block = Vector3.at(currentLocation.getX(), currentLocation.getY(), currentLocation.getZ()).add(
+                            0.5,
+                            0.5,
+                            0.5
+                    ).add(i, j, k);
+                    if (block
+                            .toBlockPoint()
+                            .clampY(getExtent().getMinY(), getExtent().getMaxY())
+                            .getBlock(getExtent())
+                            .getMaterial()
+                            .isAir()) {
+                        airDirections.add(block.subtract(currentLocation.add(0.5, 0.5, 0.5)));
+                    }
+                }
+            }
+        }
+
+        double x = 0.0;
+        double y = 0.0;
+        double z = 0.0;
+        for (Vector3 vector3 : airDirections) {
+            x += vector3.getX();
+            y += vector3.getY();
+            z += vector3.getZ();
+        }
+
+        Vector3 averageAirDirection = Vector3.at(x / airDirections.size(), y / airDirections.size(), z / airDirections.size());
+        return (Double.isNaN(averageAirDirection.getY()) ? Vector3.ZERO : averageAirDirection.normalize());
+    }
+
+    @Override
+    public Mask copy() {
+        return new SurfaceAngleMask(super.getExtent(), min, max, size);
+    }
+
+    private boolean nextToAir(BlockVector3 blockVector3) {
+        if (getExtent().getBlock(blockVector3.add(1, 0, 0)).toBaseBlock().getMaterial().isAir()) {
+            return true;
+        }
+        if (getExtent().getBlock(blockVector3.add(-1, 0, 0)).toBaseBlock().getMaterial().isAir()) {
+            return true;
+        }
+        if (getExtent().getBlock(blockVector3.add(0, 1, 0)).toBaseBlock().getMaterial().isAir()) {
+            return true;
+        }
+        if (getExtent().getBlock(blockVector3.add(0, -1, 0)).toBaseBlock().getMaterial().isAir()) {
+            return true;
+        }
+        if (getExtent().getBlock(blockVector3.add(0, 0, 1)).toBaseBlock().getMaterial().isAir()) {
+            return true;
+        }
+        return getExtent().getBlock(blockVector3.add(0, 0, -1)).toBaseBlock().getMaterial().isAir();
+    }
+
+}
diff --git a/worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/MaskFactory.java b/worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/MaskFactory.java
index f31954b2e..61f8c3015 100644
--- a/worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/MaskFactory.java
+++ b/worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/MaskFactory.java
@@ -28,6 +28,7 @@ import com.fastasyncworldedit.core.extension.factory.parser.mask.LiquidMaskParse
 import com.fastasyncworldedit.core.extension.factory.parser.mask.ROCAngleMaskParser;
 import com.fastasyncworldedit.core.extension.factory.parser.mask.RichOffsetMaskParser;
 import com.fastasyncworldedit.core.extension.factory.parser.mask.SimplexMaskParser;
+import com.fastasyncworldedit.core.extension.factory.parser.mask.SurfaceAngleMaskParser;
 import com.fastasyncworldedit.core.extension.factory.parser.mask.SurfaceMaskParser;
 import com.fastasyncworldedit.core.extension.factory.parser.mask.TrueMaskParser;
 import com.fastasyncworldedit.core.extension.factory.parser.mask.WallMaskParser;
@@ -108,6 +109,7 @@ public final class MaskFactory extends AbstractFactory<Mask> {
         register(new XAxisMaskParser(worldEdit));
         register(new YAxisMaskParser(worldEdit));
         register(new ZAxisMaskParser(worldEdit));
+        register(new SurfaceAngleMaskParser(worldEdit));
         //FAWE end
 
     }