diff --git a/sdk/bpf/c/inc/solana_sdk.h b/sdk/bpf/c/inc/solana_sdk.h
index 302492ed7d..728348f4c9 100644
--- a/sdk/bpf/c/inc/solana_sdk.h
+++ b/sdk/bpf/c/inc/solana_sdk.h
@@ -699,6 +699,7 @@ uint64_t entrypoint(const uint8_t *input);
  * Stub functions when building tests
  */
 #include <stdio.h>
+#include <stdlib.h>
 void sol_log_(const char *s, uint64_t len) {
   printf("Program log: %s\n", s);
 }