diff --git a/programs/fuzz/common.c b/programs/fuzz/common.c
index e12ee3b..465a76e 100644
--- a/programs/fuzz/common.c
+++ b/programs/fuzz/common.c
@@ -60,8 +60,11 @@
     size_t i;
 
 #if defined(MBEDTLS_CTR_DRBG_C)
-    //use mbedtls_ctr_drbg_random to find bugs in it
-    ret = mbedtls_ctr_drbg_random(p_rng, output, output_len);
+    //mbedtls_ctr_drbg_random requires a valid mbedtls_ctr_drbg_context in p_rng
+    if( p_rng != NULL ) {
+        //use mbedtls_ctr_drbg_random to find bugs in it
+        ret = mbedtls_ctr_drbg_random(p_rng, output, output_len);
+    }
 #else
     (void) p_rng;
     ret = 0;