diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc
index bb3cf6a080..7b21c80dc7 100644
--- a/src/lib/Makefile.inc
+++ b/src/lib/Makefile.inc
@@ -366,10 +366,14 @@ $(LIB_SPD_BIN): $(LIB_SPD_DEPS)
 	    (echo "HAVE_SPD_IN_CBFS is set but SPD_SOURCES is empty" && exit 1)
 	test -n "$(LIB_SPD_DEPS)" || \
 	    (echo "SPD_SOURCES is set but no SPD file was found" && exit 1)
-	for f in $(LIB_SPD_DEPS); \
-	 do for c in $$(cat $$f | grep --binary-files=text -v ^#); \
-	  do printf $$(printf '\\%o' 0x$$c); \
-	 done; \
+	for f in $(LIB_SPD_DEPS); do \
+	    if [ ! -f $$f ]; then \
+	        echo "File not found: $$f" >&2; \
+	        exit 1; \
+	    fi; \
+	    for c in $$(cat $$f | grep --binary-files=text -v ^#); \
+	        do printf $$(printf '\\%o' 0x$$c); \
+	    done; \
 	done > $@
 
 cbfs-files-y += spd.bin