diff --git a/library/bignum_core.h b/library/bignum_core.h
index bebd81032b..b32d60736c 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -377,7 +377,7 @@ mbedtls_mpi_uint mbedtls_mpi_core_add_if(mbedtls_mpi_uint *X,
  * either otherwise.
  *
  * This function operates in constant time with respect to the values
- * of \p X and \p A and \p B.
+ * of \p A and \p B.
  *
  * \param[out] X    The result of the subtraction.
  * \param[in] A     Little-endian presentation of left operand.
diff --git a/tests/suites/test_suite_bignum_core.function b/tests/suites/test_suite_bignum_core.function
index 1bb1ab06a4..bd1dfa687c 100644
--- a/tests/suites/test_suite_bignum_core.function
+++ b/tests/suites/test_suite_bignum_core.function
@@ -666,8 +666,6 @@ void mpi_core_sub(char *input_A, char *input_B,
     /* 1a) r = a - b => we should get the correct carry */
     TEST_EQUAL(carry, mbedtls_mpi_core_sub(r, a, b, limbs));
 
-    TEST_CF_PUBLIC(a, bytes);
-    TEST_CF_PUBLIC(b, bytes);
     TEST_CF_PUBLIC(r, bytes);
 
     /* 1b) r = a - b => we should get the correct result */
@@ -678,12 +676,10 @@ void mpi_core_sub(char *input_A, char *input_B,
     memcpy(r, a, bytes);
 
     TEST_CF_SECRET(r, bytes);
-    TEST_CF_SECRET(b, bytes);
 
     TEST_EQUAL(carry, mbedtls_mpi_core_sub(r, r, b, limbs));
 
     TEST_CF_PUBLIC(r, bytes);
-    TEST_CF_PUBLIC(b, bytes);
 
     /* 2b) r -= b => we should get the correct result */
     TEST_MEMORY_COMPARE(r, bytes, x, bytes);
@@ -692,12 +688,10 @@ void mpi_core_sub(char *input_A, char *input_B,
     memcpy(r, b, bytes);
 
     TEST_CF_SECRET(r, bytes);
-    TEST_CF_SECRET(a, bytes);
 
     TEST_EQUAL(carry, mbedtls_mpi_core_sub(r, a, r, limbs));
 
     TEST_CF_PUBLIC(r, bytes);
-    TEST_CF_PUBLIC(a, bytes);
 
     /* 3b) r = a - b => we should get the correct result */
     TEST_MEMORY_COMPARE(r, bytes, x, bytes);