1diff --git a/generic/tkWindow.c b/generic/tkWindow.c
2index fa25553..ad45598 100644
3--- a/generic/tkWindow.c
4+++ b/generic/tkWindow.c
5@@ -1045,6 +1045,7 @@ TkCreateMainWindow(
6
7 Tcl_SetVar2(interp, "tk_patchLevel", NULL, TK_PATCH_LEVEL, TCL_GLOBAL_ONLY);
8 Tcl_SetVar2(interp, "tk_version", NULL, TK_VERSION, TCL_GLOBAL_ONLY);
9+ Tcl_SetVar2(interp, "tk_library", NULL, TK_LIBRARY, TCL_GLOBAL_ONLY);
10
11 tsdPtr->numMainWindows++;
12 return tkwin;
13diff --git a/unix/Makefile.in b/unix/Makefile.in
14index e98070e..f417753 100644
15--- a/unix/Makefile.in
16+++ b/unix/Makefile.in
17@@ -1033,7 +1033,7 @@ tkVisual.o: $(GENERIC_DIR)/tkVisual.c
18 $(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tkVisual.c
19
20 tkWindow.o: $(GENERIC_DIR)/tkWindow.c tkUuid.h
21- $(CC) -c $(CC_SWITCHES) -I. $(GENERIC_DIR)/tkWindow.c
22+ $(CC) -c $(CC_SWITCHES) -I. -DTK_LIBRARY=\"${TK_LIBRARY}\" $(GENERIC_DIR)/tkWindow.c
23
24 tkButton.o: $(GENERIC_DIR)/tkButton.c
25 $(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tkButton.c