diff --git a/t/t4010-diff-pathspec.sh b/t/t4010-diff-pathspec.sh
index ad3d9e4845..4c4c8b1570 100755
--- a/t/t4010-diff-pathspec.sh
+++ b/t/t4010-diff-pathspec.sh
@@ -62,4 +62,12 @@ test_expect_success \
     'git diff-index --cached $tree -- file0/ >current &&
      compare_diff_raw current expected'
 
+test_expect_success 'diff-tree pathspec' '
+	tree2=$(git write-tree) &&
+	echo "$tree2" &&
+	git diff-tree -r --name-only $tree $tree2 -- pa path1/a >current &&
+	>expected &&
+	test_cmp expected current
+'
+
 test_done
diff --git a/tree-diff.c b/tree-diff.c
index 9f67af6c1f..b05d0f4355 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -118,10 +118,16 @@ static int tree_entry_interesting(struct tree_desc *desc, const char *base, int
 				continue;
 
 			/*
-			 * The base is a subdirectory of a path which
-			 * was specified, so all of them are interesting.
+			 * If the base is a subdirectory of a path which
+			 * was specified, all of them are interesting.
 			 */
-			return 2;
+			if (!matchlen ||
+			    base[matchlen] == '/' ||
+			    match[matchlen - 1] == '/')
+				return 2;
+
+			/* Just a random prefix match */
+			continue;
 		}
 
 		/* Does the base match? */