diff --git a/Pmodules.spec b/Pmodules.spec
index 0090bc7..5bb5e3e 100644
--- a/Pmodules.spec
+++ b/Pmodules.spec
@@ -66,7 +66,7 @@ sed_cmd+="s:@TCL_VERSION@:8.6:g;"
 sed_cmd+="s:@PMODULES_TMPDIR@:/var/tmp/${USER}:g;"
 sed_cmd+="s:@PMODULES_DISTFILESDIR@:${HOME}/.cache/Pmodules/distfiles:g;"
 sed_cmd+="s:@INSTALL_ROOT@:/opt/psi:g;"
-sed_cmd+="s:@PREFIX@:%{prefix}:g;"
+sed_cmd+="s:@PREFIX@:%{_prefix}:g;"
 
 libexec_dir='/usr/share/Pmodules/libexec'
 sed_cmd+="s:@BASH@:${libexec_dir}/bash:g;"