diff --git a/panda/src/glstuff/glGraphicsBuffer_src.cxx b/panda/src/glstuff/glGraphicsBuffer_src.cxx
index 46ac9a7ba6..a41c9e7f6b 100644
--- a/panda/src/glstuff/glGraphicsBuffer_src.cxx
+++ b/panda/src/glstuff/glGraphicsBuffer_src.cxx
@@ -429,9 +429,10 @@ rebuild_bitplanes() {
     if (glgsg->_use_object_labels) {
       // Assign a label for OpenGL to use when displaying debug messages.
       if (num_fbos > 1) {
-        GLchar name[128];
-        GLsizei len = snprintf(name, 128, "%s[%d]", _name.c_str(), layer);
-        glgsg->_glObjectLabel(GL_FRAMEBUFFER, _fbo[layer], len, name);
+        ostringstream strm;
+        strm << _name << '[' << layer << ']';
+        string name = strm.str();
+        glgsg->_glObjectLabel(GL_FRAMEBUFFER, _fbo[layer], name.size(), name.data());
       } else {
         glgsg->_glObjectLabel(GL_FRAMEBUFFER, _fbo[layer], _name.size(), _name.data());
       }