diff --git a/vis/include/cgl/debug.hpp b/vis/include/cgl/debug.hpp
new file mode 100644
index 0000000..4489dfd
--- /dev/null
+++ b/vis/include/cgl/debug.hpp
@@ -0,0 +1,85 @@
+#pragma once
+
+#include <glad/glad.h>
+#include <fmt/core.h>
+
+#include <string>
+
+#ifndef NDEBUG
+
+void GLAPIENTRY log_gl_debug_callback(
+    GLenum source,
+    GLenum type,
+    GLuint id,
+    GLenum severity,
+    GLsizei length,
+    const GLchar *message,
+    const void *userParam
+) {
+    std::string s_source;
+    switch (type) {
+        case GL_DEBUG_SOURCE_API:
+            s_source = "API:";
+        case GL_DEBUG_SOURCE_WINDOW_SYSTEM:
+            s_source = "WINDOW:";
+        case GL_DEBUG_SOURCE_SHADER_COMPILER:
+            s_source = "SHADER:";
+        case GL_DEBUG_SOURCE_THIRD_PARTY:
+            s_source = "3P:";
+        case GL_DEBUG_SOURCE_APPLICATION:
+            s_source = "APP:";
+        default:
+            s_source = "";
+    }
+
+    std::string s_type;
+    switch (type) {
+        case GL_DEBUG_TYPE_ERROR:
+            s_type = "ERROR:";
+            break;
+        case GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR:
+            s_type = "DEPRECATED:";
+            break;
+        case GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR:
+            s_type = "UNDEFINED:";
+            break;
+        case GL_DEBUG_TYPE_PORTABILITY:
+            s_type = "PORTABILITY:";
+            break;
+        case GL_DEBUG_TYPE_PERFORMANCE:
+            s_type = "PERFORMANCE:";
+            break;
+        case GL_DEBUG_TYPE_MARKER:
+            s_type = "MARKER:";
+            break;
+        case GL_DEBUG_TYPE_PUSH_GROUP:
+            s_type = "PUSH_GROUP:";
+            break;
+        case GL_DEBUG_TYPE_POP_GROUP:
+            s_type = "POP_GROUP:";
+            break;
+        default:
+            s_type = "";
+            break;
+    }
+
+    std::string s_severity;
+    switch (severity) {
+        case GL_DEBUG_SEVERITY_HIGH:
+            s_severity = "HIGH:";
+            break;
+        case GL_DEBUG_SEVERITY_MEDIUM:
+            s_severity = "MED:";
+            break;
+        case GL_DEBUG_SEVERITY_LOW:
+            s_severity = "LOW:";
+            break;
+        default:
+            s_severity = "INFO:";
+            break;
+    }
+
+    fmt::print(stderr, "GL:{}{}{} {}\n", s_source, s_type, s_severity, message);
+}
+
+#endif
diff --git a/vis/src/main.cpp b/vis/src/main.cpp
index 43e5b47..04c3c54 100644
--- a/vis/src/main.cpp
+++ b/vis/src/main.cpp
@@ -9,6 +9,7 @@
 #include "mirror.hpp"
 #include "solver.hpp"
 
+#include <cgl/debug.hpp>
 #include <cgl/vertexarray.hpp>
 #include <cgl/shaderprogram.hpp>
 #include <cgl/pipeline.hpp>
@@ -251,6 +252,11 @@ struct WireframeProp : public Prop<2> {
 };
 
 void run(const std::string &config_file, GLFWwindow* window) {
+#ifndef NDEBUG
+    glEnable(GL_DEBUG_OUTPUT);
+    glDebugMessageCallback(log_gl_debug_callback, nullptr);
+#endif
+
     glEnable(GL_DEPTH_TEST);
 
     glEnable(GL_BLEND);