diff --git a/include/git2/diff.h b/include/git2/diff.h
index ba2e21c27..0176d1c2f 100644
--- a/include/git2/diff.h
+++ b/include/git2/diff.h
@@ -340,7 +340,6 @@ GIT_EXTERN(int) git_diff_print_patch(
  * Directly run a text diff on two blobs.
  */
 GIT_EXTERN(int) git_diff_blobs(
-	git_repository *repo,
 	git_blob *old_blob,
 	git_blob *new_blob,
 	git_diff_options *options,
diff --git a/src/diff_output.c b/src/diff_output.c
index d5286ed68..23f74d216 100644
--- a/src/diff_output.c
+++ b/src/diff_output.c
@@ -671,7 +671,6 @@ int git_diff_print_patch(
 
 
 int git_diff_blobs(
-	git_repository *repo,
 	git_blob *old_blob,
 	git_blob *new_blob,
 	git_diff_options *options,
@@ -686,8 +685,6 @@ int git_diff_blobs(
 	xdemitconf_t xdiff_config;
 	xdemitcb_t xdiff_callback;
 
-	assert(repo);
-
 	if (options && (options->flags & GIT_DIFF_REVERSE)) {
 		git_blob *swap = old_blob;
 		old_blob = new_blob;
diff --git a/tests-clar/diff/blob.c b/tests-clar/diff/blob.c
index bdfe8baaf..ed1f14a07 100644
--- a/tests-clar/diff/blob.c
+++ b/tests-clar/diff/blob.c
@@ -43,7 +43,7 @@ void test_diff_blob__0(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		g_repo, a, b, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		a, b, &opts, &exp, diff_hunk_fn, diff_line_fn));
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 6);
@@ -53,7 +53,7 @@ void test_diff_blob__0(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		g_repo, b, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		b, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 15);
@@ -63,7 +63,7 @@ void test_diff_blob__0(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		g_repo, a, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		a, c, &opts, &exp, diff_hunk_fn, diff_line_fn));
 
 	cl_assert(exp.hunks == 1);
 	cl_assert(exp.lines == 13);
@@ -75,7 +75,7 @@ void test_diff_blob__0(void)
 
 	memset(&exp, 0, sizeof(exp));
 	cl_git_pass(git_diff_blobs(
-		g_repo, c, d, &opts, &exp, diff_hunk_fn, diff_line_fn));
+		c, d, &opts, &exp, diff_hunk_fn, diff_line_fn));
 
 	cl_assert(exp.hunks == 2);
 	cl_assert(exp.lines == 14);