diff --git a/tools/quartus/run_reg b/tools/quartus/run_reg
index f5c5d313023ddc343480ff93f6f3b58d4f1055ba..ba295263c2e809256a787224a3f439bd170617c8 100755
--- a/tools/quartus/run_reg
+++ b/tools/quartus/run_reg
@@ -111,7 +111,7 @@ fi
 unb_info $0 "Extracting peripherals from ${bspdstdir}/system.h:"
 
 # Extract lines with 'BASE' or 'SPAN', remove ALT* stuff etc., remove '0x' prefix, remove '#define' and peripheral name preceding '_SPAN', remove '_BASE', finally replace newlines with spaces.
-egrep "BASE|SPAN" ${system_h} | egrep -v 'ALT|TIMER|SYSTEM_INFO|ONCHIP_MEMORY2_0|JTAG_UART' | sed -e "s/\0x//g" | sed 's/^#define //' | sed 's/^.*_SPAN //' | sed -e "s/\_BASE//g" | sed ':a;N;$!ba;s/\n/ /g' > ${quartusdir}/${project_rev}.reg
+egrep "_BASE|_SPAN" ${system_h} | egrep -v 'ALT|TIMER|SYSTEM_INFO|ONCHIP_MEMORY2_0|JTAG_UART' | sed -e "s/\0x//g" | sed 's/^#define //' | sed 's/^.*_SPAN //' | sed -e "s/\_BASE//g" | sed ':a;N;$!ba;s/\n/ /g' > ${quartusdir}/${project_rev}.reg
 
 cat ${quartusdir}/${project_rev}.reg