diff --git a/auto/bin/make_def_fun.pl b/auto/bin/make_def_fun.pl
index 40e67d5..d6915e8 100755
--- a/auto/bin/make_def_fun.pl
+++ b/auto/bin/make_def_fun.pl
@@ -30,6 +30,8 @@ if (@ARGV)
 	foreach my $ext (sort @extlist)
 	{
 		my ($extname, $exturl, $extstring, $types, $tokens, $functions, $exacts) = parse_ext($ext);
+		print "\n#if !defined(GLEW_SUBSET) || defined(GLEW_SUBSET_$extname)\n";
 		output_decls($functions, \&make_pfn_decl);
+		print "\n#endif /* GLEW_SUBSET_$extname */\n";
 	}
 }
diff --git a/auto/bin/make_header.pl b/auto/bin/make_header.pl
index 934ef77..5ee101a 100755
--- a/auto/bin/make_header.pl
+++ b/auto/bin/make_header.pl
@@ -55,12 +55,15 @@ if (@ARGV)
 		my ($extname, $exturl, $extstring, $types, $tokens, $functions, $exacts) = parse_ext($ext);
 
 		make_separator($extname);
-		print "#ifndef $extname\n#define $extname 1\n";
+		print "#ifndef $extname\n";
 		output_tokens($tokens, \&make_define);
 		output_types($types, \&make_type);
 		output_exacts($exacts, \&make_exact);
 		output_decls($functions, \&make_pfn_type);
+		print "\n#if !defined(GLEW_SUBSET) || defined(GLEW_SUBSET_$extname)\n";
+		print "#define $extname 1\n";
 		output_decls($functions, \&make_pfn_alias);
+		print "\n#endif /* GLEW_SUBSET_$extname */\n";
 
 		my $extvar = $extname;
 		$extvar =~ s/GL(X*)_/GL$1EW_/;
diff --git a/auto/bin/make_struct_fun.pl b/auto/bin/make_struct_fun.pl
index c885960..139ad18 100755
--- a/auto/bin/make_struct_fun.pl
+++ b/auto/bin/make_struct_fun.pl
@@ -31,6 +31,8 @@ if (@ARGV)
 	foreach my $ext (sort @extlist)
 	{
 		my ($extname, $exturl, $extstring, $types, $tokens, $functions, $exacts) = parse_ext($ext);
+		print "\n#if !defined(GLEW_SUBSET) || defined(GLEW_SUBSET_$extname)\n";
 		output_decls($functions, \&make_pfn_decl);
+		print "\n#endif /* GLEW_SUBSET_$extname */\n";
 	}
 }
diff --git a/auto/src/glew_head.h b/auto/src/glew_head.h
index 9f2cf2f..3f70ce8 100644
--- a/auto/src/glew_head.h
+++ b/auto/src/glew_head.h
@@ -158,6 +158,20 @@ typedef _W64 int ptrdiff_t;
 
 #endif /* _WIN32 */
 
+/* GLEW depends on extension string entry points for internal purposes */
+
+#ifdef GLEW_SUBSET
+#ifndef GLEW_SUBSET_WGL_ARB_extensions_string
+#define GLEW_SUBSET_WGL_ARB_extensions_string
+#endif
+#ifndef GLEW_SUBSET_WGL_EXT_extensions_string
+#define GLEW_SUBSET_WGL_EXT_extensions_string
+#endif
+#ifndef GLEW_SUBSET_GLX_VERSION_1_2
+#define GLEW_SUBSET_GLX_VERSION_1_2
+#endif
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif