diff --git a/bin/render.cpp b/bin/render.cpp
index 01d32b6db..feeb4fe3f 100644
--- a/bin/render.cpp
+++ b/bin/render.cpp
@@ -78,7 +78,10 @@ int main(int argc, char *argv[]) {
 
     // Try to load the token from the environment.
     if (!token.size()) {
-        token = getenv("MAPBOX_ACCESS_TOKEN");
+        const char *token_ptr = getenv("MAPBOX_ACCESS_TOKEN");
+        if (token_ptr) {
+            token = token_ptr;
+        }
     }
 
     // Set access token if present
diff --git a/platform/default/headless_view.cpp b/platform/default/headless_view.cpp
index b0fa60fc1..d85910875 100644
--- a/platform/default/headless_view.cpp
+++ b/platform/default/headless_view.cpp
@@ -52,32 +52,36 @@ HeadlessView::HeadlessView(std::shared_ptr<HeadlessDisplay> display)
 
 void HeadlessView::loadExtensions() {
     make_active();
-    const std::string extensions = (char *)MBGL_CHECK_ERROR(glGetString(GL_EXTENSIONS));
+    const char *extension_ptr = (char *)MBGL_CHECK_ERROR(glGetString(GL_EXTENSIONS));
+
+    if (extension_ptr) {
+        const std::string extensions = extension_ptr;
 
 #ifdef MBGL_USE_CGL
-    if (extensions.find("GL_APPLE_vertex_array_object") != std::string::npos) {
-        gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)CGLGetProcAddress("glBindVertexArrayAPPLE");
-        gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)CGLGetProcAddress("glDeleteVertexArraysAPPLE");
-        gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)CGLGetProcAddress("glGenVertexArraysAPPLE");
-        gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)CGLGetProcAddress("glIsVertexArrayAPPLE");
-        assert(gl::BindVertexArray != nullptr);
-        assert(gl::DeleteVertexArrays != nullptr);
-        assert(gl::GenVertexArrays != nullptr);
-        assert(gl::IsVertexArray != nullptr);
-    }
+        if (extensions.find("GL_APPLE_vertex_array_object") != std::string::npos) {
+            gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)CGLGetProcAddress("glBindVertexArrayAPPLE");
+            gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)CGLGetProcAddress("glDeleteVertexArraysAPPLE");
+            gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)CGLGetProcAddress("glGenVertexArraysAPPLE");
+            gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)CGLGetProcAddress("glIsVertexArrayAPPLE");
+            assert(gl::BindVertexArray != nullptr);
+            assert(gl::DeleteVertexArrays != nullptr);
+            assert(gl::GenVertexArrays != nullptr);
+            assert(gl::IsVertexArray != nullptr);
+        }
 #endif
 #ifdef MBGL_USE_GLX
-    if (extensions.find("GL_ARB_vertex_array_object") != std::string::npos) {
-        gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glBindVertexArray");
-        gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glDeleteVertexArrays");
-        gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glGenVertexArrays");
-        gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glIsVertexArray");
-        assert(gl::BindVertexArray != nullptr);
-        assert(gl::DeleteVertexArrays != nullptr);
-        assert(gl::GenVertexArrays != nullptr);
-        assert(gl::IsVertexArray != nullptr);
-    }
+        if (extensions.find("GL_ARB_vertex_array_object") != std::string::npos) {
+            gl::BindVertexArray = (gl::PFNGLBINDVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glBindVertexArray");
+            gl::DeleteVertexArrays = (gl::PFNGLDELETEVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glDeleteVertexArrays");
+            gl::GenVertexArrays = (gl::PFNGLGENVERTEXARRAYSPROC)glXGetProcAddress((const GLubyte *)"glGenVertexArrays");
+            gl::IsVertexArray = (gl::PFNGLISVERTEXARRAYPROC)glXGetProcAddress((const GLubyte *)"glIsVertexArray");
+            assert(gl::BindVertexArray != nullptr);
+            assert(gl::DeleteVertexArrays != nullptr);
+            assert(gl::GenVertexArrays != nullptr);
+            assert(gl::IsVertexArray != nullptr);
+        }
 #endif
+    }
 
     make_inactive();
 }