diff --git a/pkgs/applications/editors/thonny/default.nix b/pkgs/applications/editors/thonny/default.nix
index 40ba0701ce71..a6d698b65a13 100644
--- a/pkgs/applications/editors/thonny/default.nix
+++ b/pkgs/applications/editors/thonny/default.nix
@@ -42,7 +42,6 @@ buildPythonApplication rec {
 
   preFixup = ''
     wrapProgram "$out/bin/thonny" \
-       --set TK_LIBRARY "${tk}/lib/${tk.libPrefix}" \
        --prefix PYTHONPATH : $PYTHONPATH:$(toPythonPath ${python3.pkgs.jedi})
   '';
 
@@ -64,6 +63,6 @@ buildPythonApplication rec {
     homepage = "https://www.thonny.org/";
     license = licenses.mit;
     maintainers = with maintainers; [ leenaars ];
-    platforms = platforms.linux;
+    platforms = platforms.unix;
   };
 }
diff --git a/pkgs/development/libraries/tk/8.6.nix b/pkgs/development/libraries/tk/8.6.nix
index 3e3d8ad54011..fbf456051754 100644
--- a/pkgs/development/libraries/tk/8.6.nix
+++ b/pkgs/development/libraries/tk/8.6.nix
@@ -14,4 +14,8 @@ callPackage ./generic.nix (args // {
     sha256 = "sha256-LmX6BpojNlRAo8VsVWuGc7XjKig4ANjZslfj9YTOBnU=";
   };
 
+  patches = [
+    ./tk-8_6_13-find-library.patch
+  ];
+
 })
diff --git a/pkgs/development/libraries/tk/tk-8_6_13-find-library.patch b/pkgs/development/libraries/tk/tk-8_6_13-find-library.patch
new file mode 100644
index 000000000000..a055ade80cc0
--- /dev/null
+++ b/pkgs/development/libraries/tk/tk-8_6_13-find-library.patch
@@ -0,0 +1,25 @@
+diff --git a/generic/tkWindow.c b/generic/tkWindow.c
+index fa25553..ad45598 100644
+--- a/generic/tkWindow.c
++++ b/generic/tkWindow.c
+@@ -1045,6 +1045,7 @@ TkCreateMainWindow(
+ 
+     Tcl_SetVar2(interp, "tk_patchLevel", NULL, TK_PATCH_LEVEL, TCL_GLOBAL_ONLY);
+     Tcl_SetVar2(interp, "tk_version",    NULL, TK_VERSION,     TCL_GLOBAL_ONLY);
++    Tcl_SetVar2(interp, "tk_library",    NULL, TK_LIBRARY,     TCL_GLOBAL_ONLY);
+ 
+     tsdPtr->numMainWindows++;
+     return tkwin;
+diff --git a/unix/Makefile.in b/unix/Makefile.in
+index e98070e..f417753 100644
+--- a/unix/Makefile.in
++++ b/unix/Makefile.in
+@@ -1033,7 +1033,7 @@ tkVisual.o: $(GENERIC_DIR)/tkVisual.c
+ 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tkVisual.c
+ 
+ tkWindow.o: $(GENERIC_DIR)/tkWindow.c tkUuid.h
+-	$(CC) -c $(CC_SWITCHES) -I. $(GENERIC_DIR)/tkWindow.c
++	$(CC) -c $(CC_SWITCHES) -I. -DTK_LIBRARY=\"${TK_LIBRARY}\" $(GENERIC_DIR)/tkWindow.c
+ 
+ tkButton.o: $(GENERIC_DIR)/tkButton.c
+ 	$(CC) -c $(CC_SWITCHES) $(GENERIC_DIR)/tkButton.c