--- a/configure.ac
+++ b/configure.ac
@@ -587,8 +587,8 @@
 
  .  $tcl_config_sh
 
-    CFLAGS="$CFLAGS $TCL_INCLUDE_SPEC"
-    CPPFLAGS="$CPPFLAGS $TCL_INCLUDE_SPEC"
+    CFLAGS="$CFLAGS $TCL_INCLUDE_SPEC -I/usr/include/blt"
+    CPPFLAGS="$CPPFLAGS $TCL_INCLUDE_SPEC -I/usr/include/blt"
 
     AC_CHECK_HEADERS([tcl.h blt.h], [], [AC_MSG_ERROR([Couldn't find Tcl/BLT headers])])
 
@@ -612,7 +612,7 @@
     fi
     rm -f conftest.tcl
 
-    AC_SEARCH_LIBS([Blt_GetVector], [BLT BLT24 BLT25],,
+    AC_SEARCH_LIBS([Blt_GetVector], [BLT BLT24 BLT25 Blt30],,
         [AC_MSG_ERROR([Couldnt find BLT library.])])
 
     AC_CHECK_LIB([pthread], [pthread_create])
--- a/src/tclspice.c
+++ b/src/tclspice.c
@@ -117,6 +117,9 @@
 #undef WIN32
 #endif
 #include <blt.h>
+#if BLT_MAJOR_VERSION >= 3
+#include <bltVector.h>
+#endif
 #include  "ngspice/sim.h"
 
 /* defines for Tcl support
@@ -2465,6 +2468,12 @@
         return TCL_ERROR;
 #endif
 
+#if BLT_MAJOR_VERSION >= 3
+    if (Blt_TclInit(interp) == TCL_ERROR) {
+        return TCL_ERROR;
+    }
+#endif
+
     Tcl_PkgProvide(interp, (char*) TCLSPICE_name, (char*) TCLSPICE_version);
 
     Tcl_Eval(interp, "namespace eval " TCLSPICE_namespace " { }");
--- a/examples/tclspice/tcl-testbench2/tcl-testbench2.sh
+++ b/examples/tclspice/tcl-testbench2/tcl-testbench2.sh
@@ -4,7 +4,7 @@
 
 package require BLT
 load ../../../src/.libs/libspice.so
-namespace import blt::*
+namespace import -force blt::*
 
 wm title . "Vector Test script"
 wm geometry . 800x600+40+40
--- a/examples/tclspice/tcl-testbench4/vspicechart.tcl
+++ b/examples/tclspice/tcl-testbench4/vspicechart.tcl
@@ -12,7 +12,7 @@
 source selectfromlist.tcl
 source bltGraph.tcl
 
-namespace import blt::*
+namespace import -force blt::*
 
 wm title . "vspicechart 0.01"
 wm geometry . 800x450+40+40
@@ -147,6 +147,7 @@
   set i 0
   foreach sig $globals(signals) {
     set nsig [replacechar $sig "\#" "_"]
+    catch { vector destroy $nsig }
     vector create $nsig
     spice::spicetoblt $sig $nsig
   
@@ -213,8 +214,11 @@
 pack .f2.chart -side top -fill both -expand true 
 .f2.chart axis configure x -title "Time in s"
 
-
-.f2.chart grid configure -hide no 
+if {[catch {.f2.chart grid configure -hide no}]} {
+    # BLT 3 moves grid control to the axis subcommand
+    .f2.chart axis configure x -grid yes
+    .f2.chart axis configure y -grid yes
+}
 Blt_ZoomStack .f2.chart
 Blt_Crosshairs .f2.chart
 Blt_ClosestPoint .f2.chart