diff --git a/library/pkcs12.c b/library/pkcs12.c
index a90d1f9..e725a97 100644
--- a/library/pkcs12.c
+++ b/library/pkcs12.c
@@ -218,7 +218,7 @@
     unsigned int j;
 
     unsigned char diversifier[128];
-    unsigned char salt_block[128], pwd_block[128], hash_block[128];
+    unsigned char salt_block[128], pwd_block[128], hash_block[128] = {0};
     unsigned char hash_output[MBEDTLS_MD_MAX_SIZE];
     unsigned char *p;
     unsigned char c;