diff --git a/progs/tests/vpeval.c b/progs/tests/vpeval.c
index 3e8a732..a4024b5 100644
--- a/progs/tests/vpeval.c
+++ b/progs/tests/vpeval.c
@@ -145,6 +145,11 @@
 
     printf("Using vertex program attribs? %s\n", program ? "yes" : "no");
 
+    if (program && !glutExtensionSupported("GL_NV_vertex_program")) {
+       printf("Sorry, this requires GL_NV_vertex_program\n");
+       exit(1);
+    }
+
     if (!program) {
         glMap2f(GL_MAP2_VERTEX_4,
                 0.0, 1.0, 4, 4,
diff --git a/progs/tests/vptest1.c b/progs/tests/vptest1.c
index 6e32b03..d83f9ca 100644
--- a/progs/tests/vptest1.c
+++ b/progs/tests/vptest1.c
@@ -113,6 +113,11 @@
 
    GLuint progs[5];
 
+   if (!glutExtensionSupported("GL_NV_vertex_program")) {
+      printf("Sorry, this program requires GL_NV_vertex_program\n");
+      exit(1);
+   }
+
    glGenProgramsNV(2, progs);
    assert(progs[0]);
    assert(progs[1]);
diff --git a/progs/tests/vptest2.c b/progs/tests/vptest2.c
index 4161b03..89cd6b1 100644
--- a/progs/tests/vptest2.c
+++ b/progs/tests/vptest2.c
@@ -144,6 +144,12 @@
    glutReshapeFunc( Reshape );
    glutKeyboardFunc( Key );
    glutDisplayFunc( Display );
+
+   if (!glutExtensionSupported("GL_NV_vertex_program")) {
+      printf("Sorry, this program requires GL_NV_vertex_program\n");
+      exit(1);
+   }
+
    Test1();
    Test2();
    Test3();
diff --git a/progs/tests/vptest3.c b/progs/tests/vptest3.c
index 4e4bfee..58ce227 100644
--- a/progs/tests/vptest3.c
+++ b/progs/tests/vptest3.c
@@ -93,6 +93,11 @@
 #endif
       "END\n";
 
+   if (!glutExtensionSupported("GL_NV_vertex_program")) {
+      printf("Sorry, this program requires GL_NV_vertex_program\n");
+      exit(1);
+   }
+
    glLoadProgramNV(GL_VERTEX_PROGRAM_NV, 1,
                    strlen(prog1),
                    (const GLubyte *) prog1);