diff --git a/Makefile.am b/Makefile.am
index 35d894604acbaa22aff4b9a87300ff80f12dc372..0c1dcb1036039ae3a4f4e576b2c80e156ffc8ef7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -671,12 +671,12 @@ htest/offline-tests.sh: htest/hpc-htools
 .PHONY: hs-prof hs-prof-quick
 hs-prof:
 	$(MAKE) $(AM_MAKEFLAGS) clean
-	$(MAKE) $(AM_MAKEFLAGS) $(HS_ALL_PROGS) HEXTRA="-osuf .o"
+	$(MAKE) $(AM_MAKEFLAGS) $(HS_ALL_PROGS) HEXTRA="-osuf o"
 	rm -f $(HS_ALL_PROGS)
 	$(MAKE) $(AM_MAKEFLAGS) hs-prof-quick
 
 hs-prof-quick:
-	$(MAKE) $(AM_MAKEFLAGS) $(HS_ALL_PROGS) HEXTRA="-osuf .prof_o -prof -auto-all"
+	$(MAKE) $(AM_MAKEFLAGS) $(HS_ALL_PROGS) HEXTRA="-osuf prof_o -prof -auto-all"
 
 dist_sbin_SCRIPTS = \
 	tools/ganeti-listrunner