diff --git a/src/refspec.c b/src/refspec.c
index 77c58c84e..9f0df35a7 100644
--- a/src/refspec.c
+++ b/src/refspec.c
@@ -223,7 +223,13 @@ static int refspec_transform(
 
 int git_refspec_transform(git_buf *out, const git_refspec *spec, const char *name)
 {
-        git_buf_sanitize(out);
+	assert(out && spec && name);
+	git_buf_sanitize(out);
+
+	if (!git_refspec_src_matches(spec, name)) {
+		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the source", name);
+		return -1;
+	}
 
 	if (!spec->pattern)
 		return git_buf_puts(out, spec->dst);
@@ -233,7 +239,13 @@ int git_refspec_transform(git_buf *out, const git_refspec *spec, const char *nam
 
 int git_refspec_rtransform(git_buf *out, const git_refspec *spec, const char *name)
 {
-        git_buf_sanitize(out);
+	assert(out && spec && name);
+	git_buf_sanitize(out);
+
+	if (!git_refspec_dst_matches(spec, name)) {
+		giterr_set(GITERR_INVALID, "ref '%s' doesn't match the destination", name);
+		return -1;
+	}
 
 	if (!spec->pattern)
 		return git_buf_puts(out, spec->src);
diff --git a/tests/network/refspecs.c b/tests/network/refspecs.c
index aa9b36e58..c6bcb10e8 100644
--- a/tests/network/refspecs.c
+++ b/tests/network/refspecs.c
@@ -88,7 +88,7 @@ void test_network_refspecs__parsing(void)
 	assert_refspec(GIT_DIRECTION_FETCH, "refs/pull/*/head:refs/remotes/origin/pr/*", true);
 }
 
-void assert_transform(const char *refspec, const char *name, const char *result)
+static void assert_valid_transform(const char *refspec, const char *name, const char *result)
 {
 	git_refspec spec;
 	git_buf buf = GIT_BUF_INIT;
@@ -103,8 +103,46 @@ void assert_transform(const char *refspec, const char *name, const char *result)
 
 void test_network_refspecs__transform_mid_star(void)
 {
-	assert_transform("refs/pull/*/head:refs/remotes/origin/pr/*", "refs/pull/23/head", "refs/remotes/origin/pr/23");
-	assert_transform("refs/heads/*:refs/remotes/origin/*", "refs/heads/master", "refs/remotes/origin/master");
-	assert_transform("refs/heads/*:refs/heads/*", "refs/heads/master", "refs/heads/master");
-	assert_transform("refs/*:refs/*", "refs/heads/master", "refs/heads/master");
+	assert_valid_transform("refs/pull/*/head:refs/remotes/origin/pr/*", "refs/pull/23/head", "refs/remotes/origin/pr/23");
+	assert_valid_transform("refs/heads/*:refs/remotes/origin/*", "refs/heads/master", "refs/remotes/origin/master");
+	assert_valid_transform("refs/heads/*:refs/remotes/origin/*", "refs/heads/user/feature", "refs/remotes/origin/user/feature");
+	assert_valid_transform("refs/heads/*:refs/heads/*", "refs/heads/master", "refs/heads/master");
+	assert_valid_transform("refs/heads/*:refs/heads/*", "refs/heads/user/feature", "refs/heads/user/feature");
+	assert_valid_transform("refs/*:refs/*", "refs/heads/master", "refs/heads/master");
+}
+
+static void assert_invalid_transform(const char *refspec, const char *name)
+{
+	git_refspec spec;
+	git_buf buf = GIT_BUF_INIT;
+
+	git_refspec__parse(&spec, refspec, true);
+	cl_git_fail(git_refspec_transform(&buf, &spec, name));
+
+	git_buf_free(&buf);
+	git_refspec__free(&spec);
+}
+
+void test_network_refspecs__invalid(void)
+{
+	assert_invalid_transform("refs/heads/*:refs/remotes/origin/*", "master");
+	assert_invalid_transform("refs/heads/*:refs/remotes/origin/*", "refs/headz/master");
+}
+
+static void assert_invalid_rtransform(const char *refspec, const char *name)
+{
+	git_refspec spec;
+	git_buf buf = GIT_BUF_INIT;
+
+	git_refspec__parse(&spec, refspec, true);
+	cl_git_fail(git_refspec_rtransform(&buf, &spec, name));
+
+	git_buf_free(&buf);
+	git_refspec__free(&spec);
+}
+
+void test_network_refspecs__invalid_reverse(void)
+{
+	assert_invalid_rtransform("refs/heads/*:refs/remotes/origin/*", "master");
+	assert_invalid_rtransform("refs/heads/*:refs/remotes/origin/*", "refs/remotes/o/master");
 }