diff --git a/tests/suites/test_suite_entropy.data b/tests/suites/test_suite_entropy.data
index 7460d74..abf36c0 100644
--- a/tests/suites/test_suite_entropy.data
+++ b/tests/suites/test_suite_entropy.data
@@ -7,6 +7,9 @@
 Entropy write/update seed file: nonexistent
 entropy_seed_file:"no_such_dir/file":MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR
 
+Entropy no sources
+entropy_no_sources:
+
 Entropy too many sources
 entropy_too_many_sources:
 
diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function
index 8563b11..a125f62 100644
--- a/tests/suites/test_suite_entropy.function
+++ b/tests/suites/test_suite_entropy.function
@@ -45,7 +45,6 @@
     return( 0 );
 }
 
-#if defined(MBEDTLS_ENTROPY_NV_SEED)
 /*
  * Ability to clear entropy sources to allow testing with just predefined
  * entropy sources. This function or tests depending on it might break if there
@@ -57,11 +56,12 @@
  * This might break memory checks in the future if sources need 'free-ing' then
  * as well.
  */
-void entropy_clear_sources( mbedtls_entropy_context *ctx )
+static void entropy_clear_sources( mbedtls_entropy_context *ctx )
 {
     ctx->source_count = 0;
 }
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
 /*
  * NV seed read/write functions that use a buffer instead of a file
  */
@@ -149,6 +149,22 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
+void entropy_no_sources( )
+{
+    mbedtls_entropy_context ctx;
+    unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
+
+    mbedtls_entropy_init( &ctx );
+    entropy_clear_sources( &ctx );
+    TEST_EQUAL( mbedtls_entropy_func( &ctx, buf, sizeof( buf ) ),
+                MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED );
+
+exit:
+    mbedtls_entropy_free( &ctx );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
 void entropy_too_many_sources(  )
 {
     mbedtls_entropy_context ctx;