diff --git a/lib/drmtest.c b/lib/drmtest.c
index 7e3c1d81..5f1b4ae9 100644
--- a/lib/drmtest.c
+++ b/lib/drmtest.c
@@ -717,7 +717,7 @@ out:
  * outside of places protected by drmtest_run_subtest checks - the piglit
  * runner adds every line to the subtest list.
  */
-bool drmtest_run_subtest(const char *subtest_name)
+bool __drmtest_run_subtest(const char *subtest_name)
 {
 	assert(in_subtest == false);
 
diff --git a/lib/drmtest.h b/lib/drmtest.h
index b6874117..0182e09c 100644
--- a/lib/drmtest.h
+++ b/lib/drmtest.h
@@ -98,8 +98,8 @@ void drmtest_progress(const char *header, uint64_t i, uint64_t total);
 /* subtest infrastructure */
 jmp_buf drmtest_subtest_jmpbuf;
 void drmtest_subtest_init(int argc, char **argv);
-bool drmtest_run_subtest(const char *subtest_name);
-#define drmtest_subtest_block(name) for (; drmtest_run_subtest((name)) && \
+bool __drmtest_run_subtest(const char *subtest_name);
+#define drmtest_subtest_block(name) for (; __drmtest_run_subtest((name)) && \
 					 (setjmp(drmtest_subtest_jmpbuf) == 0); \
 					 drmtest_success())
 bool drmtest_only_list_subtests(void);