diff --git a/src/csg_tree.cpp b/src/csg_tree.cpp
index 4c9bf343e..dfc4f46c7 100644
--- a/src/csg_tree.cpp
+++ b/src/csg_tree.cpp
@@ -117,6 +117,10 @@ std::shared_ptr<CsgLeafNode> SimpleBoolean(const Manifold::Impl &a,
 #ifdef MANIFOLD_DEBUG
   auto dump = [&]() {
     if (ManifoldParams().verbose) {
+      std::cout << "LHS self-intersecting: " << a.IsSelfIntersecting()
+                << std::endl;
+      std::cout << "RHS self-intersecting: " << b.IsSelfIntersecting()
+                << std::endl;
       dump_lock.lock();
       if (op == OpType::Add)
         std::cout << "Add";
diff --git a/src/impl.cpp b/src/impl.cpp
index 5a5ebc61a..7eff62ff2 100644
--- a/src/impl.cpp
+++ b/src/impl.cpp
@@ -14,8 +14,6 @@
 
 #include "./impl.h"
 
-#include <string.h>
-
 #include <algorithm>
 #include <atomic>
 #include <map>
@@ -29,6 +27,10 @@
 #include <iostream>
 #endif
 
+#ifdef MANIFOLD_DEBUG
+#include <string.h>
+#endif
+
 namespace {
 using namespace manifold;
 
diff --git a/src/properties.cpp b/src/properties.cpp
index a54666602..5b6403a6c 100644
--- a/src/properties.cpp
+++ b/src/properties.cpp
@@ -236,22 +236,14 @@ bool Manifold::Impl::IsSelfIntersecting() const {
     if (DistanceTriangleTriangleSquared(tri_x, tri_y) == 0.0) {
       // try to move the triangles around the normal of the other face
       std::array<vec3, 3> tmp_x, tmp_y;
-      for (int i : {0, 1, 2})
-        tmp_x[i] = tri_x[i] + epsilon_ * faceNormal_[y];
-      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0)
-        return true;
-      for (int i : {0, 1, 2})
-        tmp_x[i] = tri_x[i] - epsilon_ * faceNormal_[y];
-      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0)
-        return true;
-      for (int i : {0, 1, 2})
-        tmp_y[i] = tri_y[i] + epsilon_ * faceNormal_[x];
-      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0)
-        return true;
-      for (int i : {0, 1, 2})
-        tmp_y[i] = tri_y[i] - epsilon_ * faceNormal_[x];
-      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0)
-        return true;
+      for (int i : {0, 1, 2}) tmp_x[i] = tri_x[i] + epsilon_ * faceNormal_[y];
+      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0) return true;
+      for (int i : {0, 1, 2}) tmp_x[i] = tri_x[i] - epsilon_ * faceNormal_[y];
+      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0) return true;
+      for (int i : {0, 1, 2}) tmp_y[i] = tri_y[i] + epsilon_ * faceNormal_[x];
+      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0) return true;
+      for (int i : {0, 1, 2}) tmp_y[i] = tri_y[i] - epsilon_ * faceNormal_[x];
+      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0) return true;
 
 #ifdef MANIFOLD_DEBUG
       if (verbose) {