diff --git a/docs/Makefile b/docs/Makefile
index 2c0903b10a..854fb50d84 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -7,14 +7,14 @@ VERSION		:= $(shell $(MAKE) -C $(XEN_ROOT)/xen --no-print-directory xenversion)
 DOC_ARCHES      := arm x86_32 x86_64
 
 # Documentation sources to build
-MAN1SRC-y := $(wildcard man/xl*.pod.1)
-MAN1SRC-y += $(wildcard man/xenstore*.pod.1)
+MAN1SRC-y := $(sort $(wildcard man/xl*.pod.1))
+MAN1SRC-y += $(sort $(wildcard man/xenstore*.pod.1))
 
-MAN5SRC-y := $(wildcard man/xl*.pod.5)
+MAN5SRC-y := $(sort $(wildcard man/xl*.pod.5))
 
-MARKDOWNSRC-y := $(wildcard misc/*.markdown)
+MARKDOWNSRC-y := $(sort $(wildcard misc/*.markdown))
 
-TXTSRC-y := $(wildcard misc/*.txt)
+TXTSRC-y := $(sort $(wildcard misc/*.txt))
 
 
 DOC_MAN1 := $(patsubst man/%.pod.1,man1/%.1,$(MAN1SRC-y))