diff --git a/src/gl/system/gl_framebuffer.cpp b/src/gl/system/gl_framebuffer.cpp
index 24e6ee6264..a684f4c4cc 100644
--- a/src/gl/system/gl_framebuffer.cpp
+++ b/src/gl/system/gl_framebuffer.cpp
@@ -120,7 +120,10 @@ void OpenGLFrameBuffer::InitializeState()
 
 	if (first)
 	{
-		ogl_LoadFunctions();
+		if (ogl_LoadFunctions() == ogl_LOAD_FAILED)
+		{
+			I_FatalError("Failed to load OpenGL functions.");
+		}
 	}
 
 	gl_LoadExtensions();
diff --git a/src/posix/cocoa/i_video.mm b/src/posix/cocoa/i_video.mm
index 34cb4bb8b0..e741615592 100644
--- a/src/posix/cocoa/i_video.mm
+++ b/src/posix/cocoa/i_video.mm
@@ -888,7 +888,10 @@ CocoaFrameBuffer::CocoaFrameBuffer(int width, int height, bool bgra, bool fullsc
 
 	if (!isOpenGLInitialized)
 	{
-		ogl_LoadFunctions();
+		if (ogl_LoadFunctions() == ogl_LOAD_FAILED)
+		{
+			I_FatalError("Failed to load OpenGL functions.");
+		}
 		isOpenGLInitialized = true;
 	}