diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index 2d53cf9..134e49b 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -65,7 +65,7 @@
  *
  * For convenience, dies if allocation fails.
  */
-unsigned char *zero_alloc( size_t len );
+unsigned char *mbedtls_test_zero_alloc( size_t len );
 
 /**
  * Allocate and fill a buffer from hex data.
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index 358f3e4..063ebcd 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -100,7 +100,7 @@
     }
 }
 
-unsigned char *zero_alloc( size_t len )
+unsigned char *mbedtls_test_zero_alloc( size_t len )
 {
     void *p;
     size_t actual_len = ( len != 0 ) ? len : 1;
@@ -120,7 +120,7 @@
     *olen = strlen( ibuf ) / 2;
 
     if( *olen == 0 )
-        return( zero_alloc( *olen ) );
+        return( mbedtls_test_zero_alloc( *olen ) );
 
     obuf = mbedtls_calloc( 1, *olen );
     TEST_HELPER_ASSERT( obuf != NULL );
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index 9734aa0..8fe0bda 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -129,7 +129,7 @@
     dst = unhexify_alloc( hex_dst_string, &dst_len );
     TEST_ASSERT( src_len == dst_len );
 
-    output = zero_alloc( dst_len );
+    output = mbedtls_test_zero_alloc( dst_len );
 
     TEST_ASSERT( mbedtls_aes_xts_setkey_enc( &ctx, key, key_len * 8 ) == 0 );
     TEST_ASSERT( mbedtls_aes_crypt_xts( &ctx, MBEDTLS_AES_ENCRYPT, src_len,
@@ -172,7 +172,7 @@
     dst = unhexify_alloc( hex_dst_string, &dst_len );
     TEST_ASSERT( src_len == dst_len );
 
-    output = zero_alloc( dst_len );
+    output = mbedtls_test_zero_alloc( dst_len );
 
     TEST_ASSERT( mbedtls_aes_xts_setkey_dec( &ctx, key, key_len * 8 ) == 0 );
     TEST_ASSERT( mbedtls_aes_crypt_xts( &ctx, MBEDTLS_AES_DECRYPT, src_len,
diff --git a/tests/suites/test_suite_base64.function b/tests/suites/test_suite_base64.function
index 3a8bf43..dc6ec15 100644
--- a/tests/suites/test_suite_base64.function
+++ b/tests/suites/test_suite_base64.function
@@ -55,7 +55,7 @@
     unsigned char *res = NULL;
     size_t len;
 
-    res = zero_alloc( dst_buf_size );
+    res = mbedtls_test_zero_alloc( dst_buf_size );
 
     TEST_ASSERT( mbedtls_base64_encode( res, dst_buf_size, &len, src->x, src->len ) == result );
     if( result == 0 )
@@ -76,7 +76,7 @@
     unsigned char *res = NULL;
     size_t len;
 
-    res = zero_alloc( dst_buf_size );
+    res = mbedtls_test_zero_alloc( dst_buf_size );
 
     TEST_ASSERT( mbedtls_base64_decode( res, dst_buf_size, &len, (unsigned char *) src,
                                 strlen( src ) ) == result );
diff --git a/tests/suites/test_suite_pkcs5.function b/tests/suites/test_suite_pkcs5.function
index 26f1d33..ee894f1 100644
--- a/tests/suites/test_suite_pkcs5.function
+++ b/tests/suites/test_suite_pkcs5.function
@@ -43,7 +43,7 @@
     params.p = params_hex->x;
     params.len = params_hex->len;
 
-    my_out = zero_alloc( ref_out->len );
+    my_out = mbedtls_test_zero_alloc( ref_out->len );
 
     my_ret = mbedtls_pkcs5_pbes2( &params, MBEDTLS_PKCS5_DECRYPT,
                           pw->x, pw->len, data->x, data->len, my_out );