Index: test.tcl
==================================================================
--- test.tcl
+++ test.tcl
@@ -105,10 +105,11 @@
 if {[info exists ::env(TCC4TCL_TEST_RUN_NATIVE)] && $::tcl_platform(os) != "Darwin"} {
 	set tmpfile "/tmp/DELETEME_tcc4tcl_test_exec[expr rand()].so"
 	file delete $tmpfile
 	set handle [tcc4tcl::new $tmpfile "myPkg 0.1"]
 	$handle cproc ext_add {int a int b} long { return(a+b); }
+	$handle add_include_path [::tcl::pkgconfig get includedir,runtime]
 	$handle add_library_path [::tcl::pkgconfig get libdir,runtime]
 	$handle add_library_path /usr/lib/x86_64-linux-gnu
 	$handle add_library_path /usr/lib64
 	$handle add_library_path /usr/lib
 	$handle add_library_path /usr/lib32
@@ -180,5 +181,30 @@
 	callToTclBinary("test\x00test", 9);
 }
 puts [$handle code]
 $handle go
 callToTclBinaryWrapper
+
+set handle [tcc4tcl::new]
+$handle cproc testClientData {int y} {int} [concat "int x = 3;" {
+	return(x + y);
+}]
+$handle go
+set testVal [testClientData 1]
+if {$testVal != "4"} {
+	error "\[ClientData\] Invalid value: $testVal, should have been 4"
+}
+
+set handle [tcc4tcl::new]
+$handle cproc testClientData {ClientData _x=3 int y} {int} {
+	int x
+
+	Tcl_GetIntFromObj(NULL, _x, &x);
+
+	return(x + y);
+}
+set testVal [testClientData 1]
+if {$testVal != "4"} {
+	error "\[ClientData\] Invalid value: $testVal, should have been 4"
+}
+
+exit 0