diff --git a/src/FlatLayerVisualisation.cpp b/src/FlatLayerVisualisation.cpp
index 72e60c1..24f108e 100644
--- a/src/FlatLayerVisualisation.cpp
+++ b/src/FlatLayerVisualisation.cpp
@@ -7,7 +7,7 @@
 using namespace std;
 using namespace fmri;
 
-static inline void computeColor(float intensity, float limit, float* destination)
+static inline void computeColor(float intensity, float limit, float *destination)
 {
     const float saturation = min(-log(abs(intensity) / limit) / 10.0f, 1.0f);
     if (intensity > 0) {
@@ -29,7 +29,7 @@ FlatLayerVisualisation::FlatLayerVisualisation(const LayerData &layer, Ordering
         colorBuffer(new float[faceCount * 3]),
         indexBuffer(new int[faceCount * 3])
 {
-    auto& shape = layer.shape();
+    auto &shape = layer.shape();
     CHECK_EQ(shape.size(), 2) << "layer should be flat!" << endl;
     CHECK_EQ(shape[0], 1) << "Only single images supported." << endl;
 
@@ -37,7 +37,8 @@ FlatLayerVisualisation::FlatLayerVisualisation(const LayerData &layer, Ordering
 
     const auto limit = (int) layer.numEntries();
     auto data = layer.data();
-    const auto [minElem, maxElem] = minmax_element(data, data + limit);
+    const auto
+    [minElem, maxElem] = minmax_element(data, data + limit);
 
     auto scalingMax = max(abs(*minElem), abs(*maxElem));
 
@@ -67,9 +68,16 @@ void FlatLayerVisualisation::render()
     glVertexPointer(3, GL_FLOAT, 0, vertexBuffer.get());
     glColorPointer(3, GL_FLOAT, 0, colorBuffer.get());
     glDrawElements(GL_TRIANGLES, faceCount * 3, GL_UNSIGNED_INT, indexBuffer.get());
+    glDisableClientState(GL_COLOR_ARRAY);
+
+    // Now draw wireframe
+    glColor4f(0, 0, 0, 1);
+    glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+    glDrawElements(GL_TRIANGLES, faceCount * 3, GL_UNSIGNED_INT, indexBuffer.get());
+    glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+
 
     glDisableClientState(GL_VERTEX_ARRAY);
-    glDisableClientState(GL_COLOR_ARRAY);
 }
 
 void FlatLayerVisualisation::setVertexPositions(const int vertexNo, float *destination)