diff --git a/pkgs/development/interpreters/php/generic.nix b/pkgs/development/interpreters/php/generic.nix
index 13fd811c4ea..46ca2e6ebda 100644
--- a/pkgs/development/interpreters/php/generic.nix
+++ b/pkgs/development/interpreters/php/generic.nix
@@ -125,15 +125,15 @@ let
                   ln -s ${extraInit} $out/lib/php.ini
 
                   if test -e $out/bin/php; then
-                    wrapProgram $out/bin/php --set PHP_INI_SCAN_DIR $out/lib
+                    wrapProgram $out/bin/php --prefix PHP_INI_SCAN_DIR : $out/lib
                   fi
 
                   if test -e $out/bin/php-fpm; then
-                    wrapProgram $out/bin/php-fpm --set PHP_INI_SCAN_DIR $out/lib
+                    wrapProgram $out/bin/php-fpm --prefix PHP_INI_SCAN_DIR : $out/lib
                   fi
 
                   if test -e $out/bin/phpdbg; then
-                    wrapProgram $out/bin/phpdbg --set PHP_INI_SCAN_DIR $out/lib
+                    wrapProgram $out/bin/phpdbg --prefix PHP_INI_SCAN_DIR : $out/lib
                   fi
                 '';
               };