diff --git a/edition/voxel_tool.cpp b/edition/voxel_tool.cpp
index 26adbfa1..5e89db84 100644
--- a/edition/voxel_tool.cpp
+++ b/edition/voxel_tool.cpp
@@ -161,7 +161,7 @@ inline float sdf_blend(float src_value, float dst_value, VoxelTool::Mode mode) {
 
 		case VoxelTool::MODE_REMOVE:
 			// Relative complement (or difference)
-			res = sdf_subtract(src_value, dst_value);
+			res = sdf_subtract(dst_value, src_value);
 			break;
 
 		case VoxelTool::MODE_SET:
diff --git a/generators/graph/range_utility.h b/generators/graph/range_utility.h
index 93425e6c..a293ab08 100644
--- a/generators/graph/range_utility.h
+++ b/generators/graph/range_utility.h
@@ -24,7 +24,7 @@ inline Interval sdf_union(Interval a, Interval b) {
 
 // Does a - b
 inline Interval sdf_subtract(Interval a, Interval b) {
-	return max_interval(a, b);
+	return max_interval(a, -b);
 }
 
 Interval sdf_smooth_union(Interval p_b, Interval p_a, float p_s);
diff --git a/util/math/sdf.h b/util/math/sdf.h
index 818bb877..63f9665d 100644
--- a/util/math/sdf.h
+++ b/util/math/sdf.h
@@ -38,9 +38,9 @@ inline float sdf_union(float a, float b) {
 	return min(a, b);
 }
 
-// Subtracts SDF a from SDF b
+// Subtracts SDF b from SDF a
 inline float sdf_subtract(float a, float b) {
-	return max(-a, b);
+	return max(a, -b);
 }
 
 inline float sdf_smooth_union(float a, float b, float s) {
@@ -48,7 +48,7 @@ inline float sdf_smooth_union(float a, float b, float s) {
 	return Math::lerp(b, a, h) - s * h * (1.0f - h);
 }
 
-// Inverted a and b because it subtracts SDF b from SDF a
+// Inverted a and b because it subtracts SDF a from SDF b
 inline float sdf_smooth_subtract(float b, float a, float s) {
 	float h = clamp(0.5f - 0.5f * (b + a) / s, 0.0f, 1.0f);
 	return Math::lerp(b, -a, h) + s * h * (1.0f - h);