diff --git a/rules.mak b/rules.mak
index 5941b73eb5..7e10432596 100644
--- a/rules.mak
+++ b/rules.mak
@@ -40,7 +40,7 @@ cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
               >/dev/null 2>&1 && echo OK), $2, $3)
 
 VPATH_SUFFIXES = %.c %.h %.S %.m %.mak %.texi
-set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES), $(eval vpath $(PATTERN) $1)))
+set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))
 
 # Generate timestamp files for .h include files