diff --git a/cpp/opengl/render_context_glx.cpp b/cpp/opengl/render_context_glx.cpp
index 93ddba0..78cfb4f 100644
--- a/cpp/opengl/render_context_glx.cpp
+++ b/cpp/opengl/render_context_glx.cpp
@@ -161,14 +161,14 @@ rk_window_t rk_create_context(
     XStoreName(rk_display, rk_window, name);
     XMapWindow(rk_display, rk_window);
 
-    char const * const glxExts = glXQueryExtensionsString(rk_display, DefaultScreen(rk_display));
+    char const * const glx_exts = glXQueryExtensionsString(rk_display, DefaultScreen(rk_display));
     glXCreateContextAttribsARBProc const glXCreateContextAttribsARB =
         reinterpret_cast<glXCreateContextAttribsARBProc>(
             glXGetProcAddressARB(reinterpret_cast<const GLubyte *>("glXCreateContextAttribsARB")));
 
     rk_error_occured = false;
     int (*oldHandler)(Display *, XErrorEvent *) = XSetErrorHandler(&rk_error_handler);
-    if (!rk_extension_supported(glxExts, "GLX_ARB_create_context") || !glXCreateContextAttribsARB) {
+    if (!rk_extension_supported(glx_exts, "GLX_ARB_create_context") || !glXCreateContextAttribsARB) {
         rk_printf("glXCreateContextAttribsARB() extension not found.");
         rk_destroy_context();
         return nullptr;
@@ -188,13 +188,14 @@ rk_window_t rk_create_context(
     }
     glXMakeCurrent(rk_display, rk_window, rk_context);
 
-    if (rk_extension_supported(glxExts, "GL_EXT_base_instance")) {
+    char const * const gl_exts = reinterpret_cast<char const *>(glGetString(GL_EXTENSIONS));
+    if (rk_extension_supported(gl_exts, "GL_EXT_base_instance")) {
         rk_DrawElementsInstancedBaseInstance =
             reinterpret_cast<PFNGLDRAWELEMENTSINSTANCEDBASEINSTANCEPROC>(
                 glXGetProcAddressARB(reinterpret_cast<const GLubyte *>("DrawElementsInstancedBaseInstance")));
         if (rk_DrawElementsInstancedBaseInstance) {
             rk_printf("Using extension GL_EXT_base_instance::DrawElementsInstancedBaseInstance.");
-            if (rk_extension_supported(glxExts, "GL_EXT_multi_draw_indirect")) {
+            if (rk_extension_supported(gl_exts, "GL_EXT_multi_draw_indirect")) {
                 rk_MultiDrawElementsIndirect =
                     reinterpret_cast<PFNGLMULTIDRAWELEMENTSINDIRECTPROC>(
                         glXGetProcAddressARB(reinterpret_cast<const GLubyte *>("MultiDrawElementsIndirectEXT")));