diff --git a/gitk b/gitk
index ee696b301ed406935b5ad521bff33ea398ce51ea..52bb0e9d35f74cec7b45956aaf59532c0cad7019 100755
--- a/gitk
+++ b/gitk
@@ -23,6 +23,26 @@ proc reponame {} {
     return [file tail $n]
 }
 
+proc gitworktree {} {
+    variable _gitworktree
+    if {[info exists _gitworktree]} {
+	return $_gitworktree
+    }
+    # v1.7.0 introduced --show-toplevel to return the canonical work-tree
+    if {[catch {set _gitworktree [exec git rev-parse --show-toplevel]}]} {
+        # try to set work tree from environment, core.worktree or use
+        # cdup to obtain a relative path to the top of the worktree. If
+        # run from the top, the ./ prefix ensures normalize expands pwd.
+        if {[catch { set _gitworktree $env(GIT_WORK_TREE) }]} {
+	    catch {set _gitworktree [exec git config --get core.worktree]}
+	    if {$_gitworktree eq ""} {
+		set _gitworktree [file normalize ./[exec git rev-parse --show-cdup]]
+	    }
+        }
+    }
+    return $_gitworktree
+}
+
 # A simple scheduler for compute-intensive stuff.
 # The aim is to make sure that event handlers for GUI actions can
 # run at least every 50-100 ms.  Unfortunately fileevent handlers are
@@ -7402,19 +7422,15 @@ proc startdiff {ids} {
     }
 }
 
+# If the filename (name) is under any of the passed filter paths
+# then return true to include the file in the listing.
 proc path_filter {filter name} {
+    set worktree [gitworktree]
     foreach p $filter {
-	set l [string length $p]
-	if {[string index $p end] eq "/"} {
-	    if {[string compare -length $l $p $name] == 0} {
-		return 1
-	    }
-	} else {
-	    if {[string compare -length $l $p $name] == 0 &&
-		([string length $name] == $l ||
-		 [string index $name $l] eq "/")} {
-		return 1
-	    }
+	set fq_p [file normalize $p]
+	set fq_n [file normalize [file join $worktree $name]]
+	if {[string match [file normalize $fq_p]* $fq_n]} {
+	    return 1
 	}
     }
     return 0