diff --git a/gitk b/gitk
index 899b51ca55..11ad639d06 100755
--- a/gitk
+++ b/gitk
@@ -58,7 +58,7 @@ if {[is_Windows]} {
         set i $from_index
         while {$i < [llength $command_line]} {
             set cmd [lindex $command_line $i]
-            if {[file pathtype $cmd] ne "absolute"} {
+            if {[llength [file split $cmd]] < 2} {
                 set fullpath [_which $cmd]
                 if {$fullpath eq ""} {
                     throw {NOT-FOUND} "$cmd not found in PATH"