diff --git a/tests/suites/test_suite_ctr_drbg.data b/tests/suites/test_suite_ctr_drbg.data
index 312910e..5f198a4 100644
--- a/tests/suites/test_suite_ctr_drbg.data
+++ b/tests/suites/test_suite_ctr_drbg.data
@@ -1070,8 +1070,14 @@
 depends_on:MBEDTLS_CTR_DRBG_USE_128_BIT_KEY
 ctr_drbg_validate_pr:"d4f1f4ae08bcb3e1":"5d4041942bcf68864a4997d8171f1f9fef55a769b7eaf03fe082029bb32a2b9d8239e865c0a42e14b964b9c09de85a20":"":"":"4155320287eedcf7d484c2c2a1e2eb64b9c9ce77c87202a1ae1616c7a5cfd1c687c7a0bfcc85bda48fdd4629fd330c22d0a76076f88fc7cd04037ee06b7af602"
 
-CTR_DRBG entropy usage
-ctr_drbg_entropy_usage:
+CTR_DRBG entropy usage (entropy_nonce_len=0 by default)
+ctr_drbg_entropy_usage:-1
+
+CTR_DRBG entropy usage (entropy_nonce_len=0)
+ctr_drbg_entropy_usage:0
+
+CTR_DRBG entropy usage (entropy_nonce_len=7)
+ctr_drbg_entropy_usage:7
 
 CTR_DRBG write/update seed file [#1]
 ctr_drbg_seed_file:"data_files/ctr_drbg_seed":0
diff --git a/tests/suites/test_suite_ctr_drbg.function b/tests/suites/test_suite_ctr_drbg.function
index 2b95062..02f9eca 100644
--- a/tests/suites/test_suite_ctr_drbg.function
+++ b/tests/suites/test_suite_ctr_drbg.function
@@ -190,7 +190,7 @@
 
 
 /* BEGIN_CASE */
-void ctr_drbg_entropy_usage(  )
+void ctr_drbg_entropy_usage( int entropy_nonce_len )
 {
     unsigned char out[16];
     unsigned char add[16];
@@ -206,9 +206,14 @@
     memset( out, 0, sizeof( out ) );
     memset( add, 0, sizeof( add ) );
 
+    if( entropy_nonce_len >= 0 )
+        TEST_ASSERT( mbedtls_ctr_drbg_set_nonce_len( &ctx, entropy_nonce_len ) == 0 );
+
     /* Init must use entropy */
     TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, mbedtls_test_entropy_func, entropy, NULL, 0 ) == 0 );
     expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN;
+    if( entropy_nonce_len >= 0 )
+        expected_idx += entropy_nonce_len;
     TEST_EQUAL( test_offset_idx, expected_idx );
 
     /* By default, PR is off and reseed_interval is large,