diff --git a/manual/Makefile b/manual/Makefile
index 410d5a68f5..e1d3c1fb81 100644
--- a/manual/Makefile
+++ b/manual/Makefile
@@ -18,7 +18,7 @@ INCLUDES= $(TARGET_INC) -I$(FIRMDIR)/include -I$(FIRMDIR)/export -I. -I$(BUILDDI
 .PHONY: all buildmanual clean objdir-check
 MANFILE := rockbox-build
 
-VERSION= `$(TOOLSDIR)/version.sh $(ROOTDIR)`
+VERSION ?= $(shell $(TOOLSDIR)/version.sh $(ROOTDIR))
 
 .PHONY: $(OBJDIR)/version.tex $(OBJDIR)/$(MANFILE).tex
 
diff --git a/manual/Makefile.pdflatex b/manual/Makefile.pdflatex
index c533e0fed0..ad58315606 100644
--- a/manual/Makefile.pdflatex
+++ b/manual/Makefile.pdflatex
@@ -6,7 +6,7 @@ HTLATEX := htlatex
 HTOPTS1 := rockbox-html,charset=utf-8,early_
 HTOPTS2 := " -utf8 -cmozhtf"
 HTOPTS3 := "-dhtml/ -cvalidate"
-VERSION=`$(TOOLSDIR)/version.sh $(ROOTDIR)`
+VERSION ?= $(shell $(TOOLSDIR)/version.sh $(ROOTDIR))
 SPLITHTML ?= 2
 
 .PHONY: all cleaner buildmanual output