diff --git a/ChangeLog b/ChangeLog
index 9ed7b4c..e1588f5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,7 @@
      Christian Walther in #2239.
    * Fix potential memory leak in X.509 self test. Found and fixed by
      Junhwan Park, #2106.
+   * Reduce stack usage of hkdf tests. Fixes #2195.
 
 Changes
    * Server's RSA certificate in certs.c was SHA-1 signed. In the default
diff --git a/tests/suites/test_suite_hkdf.function b/tests/suites/test_suite_hkdf.function
index c85a51a..3e87207 100644
--- a/tests/suites/test_suite_hkdf.function
+++ b/tests/suites/test_suite_hkdf.function
@@ -14,12 +14,16 @@
 {
     int ret;
     size_t ikm_len, salt_len, info_len, okm_len;
-    unsigned char ikm[1024] = { '\0' };
-    unsigned char salt[1024] = { '\0' };
-    unsigned char info[1024] = { '\0' };
-    unsigned char expected_okm[1024] = { '\0' };
-    unsigned char okm[1024] = { '\0' };
-    unsigned char okm_string[1000] = { '\0' };
+    unsigned char ikm[128] = { '\0' };
+    unsigned char salt[128] = { '\0' };
+    unsigned char info[128] = { '\0' };
+    unsigned char expected_okm[128] = { '\0' };
+    unsigned char okm[128] = { '\0' };
+    /*
+     * okm_hex is the string representation of okm,
+     * so its size is twice the size of okm, and an extra null-termination.
+     */
+    unsigned char okm_hex[257] = { '\0' };
 
     const mbedtls_md_info_t *md = mbedtls_md_info_from_type( md_alg );
     TEST_ASSERT( md != NULL );
@@ -34,8 +38,8 @@
     TEST_ASSERT( ret == 0 );
 
     // Run hexify on it so that it looks nicer if the assertion fails
-    hexify( okm_string, okm, okm_len );
-    TEST_ASSERT( !strcmp( (char *)okm_string, hex_okm_string ) );
+    hexify( okm_hex, okm, okm_len );
+    TEST_ASSERT( !strcmp( (char *)okm_hex, hex_okm_string ) );
 }
 /* END_CASE */