diff --git a/auto/src/glew_gl.c b/auto/src/glew_gl.c
index 4c956f9..e429c49 100644
--- a/auto/src/glew_gl.c
+++ b/auto/src/glew_gl.c
@@ -62,13 +62,13 @@ GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
   s = glGetString(GL_VERSION);
   if (!s) return GLEW_ERROR_NO_GL_VERSION;
   i = _glewStrCLen(s, '.')+1;
-  if (s+i == NULL || s[i] < '1')
+  if (s+i-1 == NULL || s+i == NULL || s[i] < '1')
   {
     return GLEW_ERROR_GL_VERSION_10_ONLY;
   }
   else
   {
-    if (s[3] >= '5')
+    if (s[i] >= '5')
     {
       GLEW_VERSION_1_1 = GL_TRUE;
       GLEW_VERSION_1_2 = GL_TRUE;
@@ -76,7 +76,7 @@ GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
       GLEW_VERSION_1_4 = GL_TRUE;
       GLEW_VERSION_1_5 = GL_TRUE;
     }
-    if (s[2] == '4')
+    if (s[i] == '4')
     {
       GLEW_VERSION_1_1 = GL_TRUE;
       GLEW_VERSION_1_2 = GL_TRUE;
@@ -84,7 +84,7 @@ GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
       GLEW_VERSION_1_4 = GL_TRUE;
       GLEW_VERSION_1_5 = GL_FALSE;
     }
-    if (s[2] == '3')
+    if (s[i] == '3')
     {
       GLEW_VERSION_1_1 = GL_TRUE;
       GLEW_VERSION_1_2 = GL_TRUE;
@@ -92,7 +92,7 @@ GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
       GLEW_VERSION_1_4 = GL_FALSE;
       GLEW_VERSION_1_5 = GL_FALSE;
     }
-    if (s[2] == '2')
+    if (s[i] == '2')
     {
       GLEW_VERSION_1_1 = GL_TRUE;
       GLEW_VERSION_1_2 = GL_TRUE;
@@ -100,7 +100,7 @@ GLenum glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
       GLEW_VERSION_1_4 = GL_FALSE;
       GLEW_VERSION_1_5 = GL_FALSE;
     }
-    if (s[2] < '2')
+    if (s[i] < '2')
     {
       GLEW_VERSION_1_1 = GL_TRUE;
       GLEW_VERSION_1_2 = GL_FALSE;