diff --git a/tools/perf/util/PERF-VERSION-GEN b/tools/perf/util/PERF-VERSION-GEN
index 97d7656..26d4d3f 100755
--- a/tools/perf/util/PERF-VERSION-GEN
+++ b/tools/perf/util/PERF-VERSION-GEN
@@ -23,10 +23,10 @@
 then
 	VN=$(echo "$VN" | sed -e 's/-/./g');
 else
-	eval `grep '^VERSION\s*=' ../../Makefile|tr -d ' '`
-	eval `grep '^PATCHLEVEL\s*=' ../../Makefile|tr -d ' '`
-	eval `grep '^SUBLEVEL\s*=' ../../Makefile|tr -d ' '`
-	eval `grep '^EXTRAVERSION\s*=' ../../Makefile|tr -d ' '`
+	eval $(grep '^VERSION[[:space:]]*=' ../../Makefile|tr -d ' ')
+	eval $(grep '^PATCHLEVEL[[:space:]]*=' ../../Makefile|tr -d ' ')
+	eval $(grep '^SUBLEVEL[[:space:]]*=' ../../Makefile|tr -d ' ')
+	eval $(grep '^EXTRAVERSION[[:space:]]*=' ../../Makefile|tr -d ' ')
 
 	VN="${VERSION}.${PATCHLEVEL}.${SUBLEVEL}${EXTRAVERSION}"
 fi