diff --git a/.gitignore b/.gitignore
index 9229e918cd..fa7ac93594 100644
--- a/.gitignore
+++ b/.gitignore
@@ -149,6 +149,7 @@ test-chmtime
 test-date
 test-delta
 test-dump-cache-tree
+test-genrandom
 test-match-trees
 common-cmds.h
 *.tar.gz
diff --git a/Makefile b/Makefile
index a77d31de98..bd0ba95b1a 100644
--- a/Makefile
+++ b/Makefile
@@ -932,7 +932,7 @@ endif
 
 export NO_SVN_TESTS
 
-test: all test-chmtime$X
+test: all test-chmtime$X test-genrandom$X
 	$(MAKE) -C t/ all
 
 test-date$X: test-date.c date.o ctype.o
@@ -953,6 +953,9 @@ test-match-trees$X: test-match-trees.o $(GITLIBS)
 test-chmtime$X: test-chmtime.c
 	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $<
 
+test-genrandom$X: test-genrandom.c
+	$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $<
+
 check-sha1:: test-sha1$X
 	./test-sha1.sh
 
@@ -1041,7 +1044,7 @@ dist-doc:
 
 clean:
 	rm -f *.o mozilla-sha1/*.o arm/*.o ppc/*.o compat/*.o xdiff/*.o \
-		test-chmtime$X $(LIB_FILE) $(XDIFF_LIB)
+		test-chmtime$X test-genrandom$X $(LIB_FILE) $(XDIFF_LIB)
 	rm -f $(ALL_PROGRAMS) $(BUILT_INS) git$X
 	rm -f *.spec *.pyc *.pyo */*.pyc */*.pyo common-cmds.h TAGS tags
 	rm -rf autom4te.cache
diff --git a/test-genrandom.c b/test-genrandom.c
new file mode 100644
index 0000000000..8cefe6cfed
--- /dev/null
+++ b/test-genrandom.c
@@ -0,0 +1,34 @@
+/*
+ * Simple random data generator used to create reproducible test files.
+ * This is inspired from POSIX.1-2001 implementation example for rand().
+ * Copyright (C) 2007 by Nicolas Pitre, licensed under the GPL version 2.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(int argc, char *argv[])
+{
+	unsigned long count, next = 0;
+	unsigned char *c;
+
+	if (argc < 2 || argc > 3) {
+		fprintf( stderr, "Usage: %s <seed_string> [<size>]", argv[0]);
+		return 1;
+	}
+
+	c = (unsigned char *) argv[1];
+	do {
+		next = next * 11 + *c;
+	} while (*c++);
+
+	count = (argc == 3) ? strtoul(argv[2], NULL, 0) : -1L;
+
+	while (count--) {
+		next = next * 1103515245 + 12345;
+		if (putchar((next >> 16) & 0xff) == EOF)
+			return -1;
+	}
+
+	return 0;
+}