diff --git a/build/ab.mk b/build/ab.mk
index 2e15af18..2122439e 100644
--- a/build/ab.mk
+++ b/build/ab.mk
@@ -50,8 +50,8 @@ EXT ?=
 ifeq ($(PROGRESSINFO),)
 # The first make invocation here has to have its output discarded or else it
 # produces spurious 'Leaving directory' messages... don't know why.
-rulecount := $(shell $(MAKE) --no-print-directory -q $(OBJ)/build.mk PROGRESSINFO=1 > /dev/null \
-	&& $(MAKE) --no-print-directory -n $(MAKECMDGOALS) PROGRESSINFO=XXXPROGRESSINFOXXX | grep XXXPROGRESSINFOXXX | wc -l)
+rulecount := $(strip $(shell $(MAKE) --no-print-directory -q $(OBJ)/build.mk PROGRESSINFO=1 > /dev/null \
+	&& $(MAKE) --no-print-directory -n $(MAKECMDGOALS) PROGRESSINFO=XXXPROGRESSINFOXXX | grep XXXPROGRESSINFOXXX | wc -l))
 ruleindex := 1
 PROGRESSINFO = "[$(ruleindex)/$(rulecount)]$(eval ruleindex := $(shell expr $(ruleindex) + 1))"
 endif