diff --git a/GL/framebuffer.c b/GL/framebuffer.c
index cd77798..9af7575 100644
--- a/GL/framebuffer.c
+++ b/GL/framebuffer.c
@@ -206,6 +206,13 @@ void APIENTRY glGenerateMipmapEXT(GLenum target) {
 
     TextureObject* tex = _glGetBoundTexture();
 
+    if(tex->width != tex->height) {
+        fprintf(stderr, "[GL ERROR] Mipmaps cannot be supported on non-square textures\n");
+        _glKosThrowError(GL_INVALID_OPERATION, __func__);
+        _glKosPrintError();
+        return;
+    }
+
     if(!tex || !tex->data || !tex->mipmapCount) {
         _glKosThrowError(GL_INVALID_OPERATION, __func__);
         _glKosPrintError();
diff --git a/GL/texture.c b/GL/texture.c
index 62bc950..f3a1662 100644
--- a/GL/texture.c
+++ b/GL/texture.c
@@ -852,6 +852,11 @@ void APIENTRY glTexImage2D(GLenum target, GLint level, GLint internalFormat,
         _glKosThrowError(GL_INVALID_VALUE, "glTexImage2D");
     }
 
+    if(level > 0 && width != height) {
+        fprintf(stderr, "[GL ERROR] Mipmaps cannot be supported on non-square textures\n");
+        _glKosThrowError(GL_INVALID_OPERATION, __func__);
+    }
+
     if(border) {
         _glKosThrowError(GL_INVALID_VALUE, "glTexImage2D");
     }