diff --git a/diff-cache.c b/diff-cache.c
index 603a6b7774..33b3b31779 100644
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -193,7 +193,8 @@ int main(int argc, const char **argv)
 			/* We accept the -r flag just to look like git-diff-tree */
 			continue;
 		}
-		if (!strcmp(arg, "-p")) {
+		/* We accept the -u flag as a synonym for "-p" */
+		if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
 			diff_output_format = DIFF_FORMAT_PATCH;
 			continue;
 		}
diff --git a/diff-files.c b/diff-files.c
index 4d60017e46..3221e31979 100644
--- a/diff-files.c
+++ b/diff-files.c
@@ -45,7 +45,7 @@ int main(int argc, const char **argv)
 	int i;
 
 	while (1 < argc && argv[1][0] == '-') {
-		if (!strcmp(argv[1], "-p"))
+		if (!strcmp(argv[1], "-p") || !strcmp(argv[1], "-u"))
 			diff_output_format = DIFF_FORMAT_PATCH;
 		else if (!strcmp(argv[1], "-q"))
 			silent = 1;
diff --git a/diff-tree.c b/diff-tree.c
index 60ad2b5b6c..ea237051ee 100644
--- a/diff-tree.c
+++ b/diff-tree.c
@@ -438,7 +438,7 @@ int main(int argc, const char **argv)
 			diff_setup_opt |= DIFF_SETUP_REVERSE;
 			continue;
 		}
-		if (!strcmp(arg, "-p")) {
+		if (!strcmp(arg, "-p") || !strcmp(arg, "-u")) {
 			diff_output_format = DIFF_FORMAT_PATCH;
 			recursive = 1;
 			continue;