diff --git a/library/bignum.c b/library/bignum.c
index 0e7b3cea02..2e5ad96ffa 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -63,19 +63,8 @@
 #define MPI_VALIDATE( cond )                                           \
     MBEDTLS_INTERNAL_VALIDATE( cond )
 
-#define ciL    (sizeof(mbedtls_mpi_uint))         /* chars in limb  */
-#define biL    (ciL << 3)               /* bits  in limb  */
-#define biH    (ciL << 2)               /* half limb size */
-
 #define MPI_SIZE_T_MAX  ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
 
-/*
- * Convert between bits/chars and number of limbs
- * Divide first in order to avoid potential overflows
- */
-#define BITS_TO_LIMBS(i)  ( (i) / biL + ( (i) % biL != 0 ) )
-#define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )
-
 /* Implementation that should never be optimized out by the compiler */
 static void mbedtls_mpi_zeroize( mbedtls_mpi_uint *v, size_t n )
 {
@@ -304,10 +293,6 @@ int mbedtls_mpi_get_bit( const mbedtls_mpi *X, size_t pos )
     return( ( X->p[pos / biL] >> ( pos % biL ) ) & 0x01 );
 }
 
-/* Get a specific byte, without range checks. */
-#define GET_BYTE( X, i )                                \
-    ( ( ( X )->p[( i ) / ciL] >> ( ( ( i ) % ciL ) * 8 ) ) & 0xff )
-
 /*
  * Set a bit to a specific value of 0 or 1
  */
diff --git a/library/bignum_core.c b/library/bignum_core.c
index 3c083a4389..ab7d8e1484 100644
--- a/library/bignum_core.c
+++ b/library/bignum_core.c
@@ -38,20 +38,6 @@
 
 #include "bignum_core.h"
 
-#define ciL    (sizeof(mbedtls_mpi_uint))   /* chars in limb  */
-#define biL    (ciL << 3)                   /* bits  in limb  */
-#define biH    (ciL << 2)                   /* half limb size */
-
-/*
- * Convert between bits/chars and number of limbs
- * Divide first in order to avoid potential overflows
- */
-#define BITS_TO_LIMBS(i)  ( (i) / biL + ( (i) % biL != 0 ) )
-#define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )
-/* Get a specific byte, without range checks. */
-#define GET_BYTE( X, i )                                \
-    ( ( ( X )[( i ) / ciL] >> ( ( ( i ) % ciL ) * 8 ) ) & 0xff )
-
 /*
  * Count leading zero bits in a given integer
  */
diff --git a/library/bignum_core.h b/library/bignum_core.h
index 2141640cfd..3a789272c4 100644
--- a/library/bignum_core.h
+++ b/library/bignum_core.h
@@ -122,4 +122,18 @@ int mbedtls_mpi_core_write_be( const mbedtls_mpi_uint *X,
                                unsigned char *buf,
                                size_t buflen );
 
+#define ciL    (sizeof(mbedtls_mpi_uint))   /* chars in limb  */
+#define biL    (ciL << 3)                   /* bits  in limb  */
+#define biH    (ciL << 2)                   /* half limb size */
+
+/*
+ * Convert between bits/chars and number of limbs
+ * Divide first in order to avoid potential overflows
+ */
+#define BITS_TO_LIMBS(i)  ( (i) / biL + ( (i) % biL != 0 ) )
+#define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )
+/* Get a specific byte, without range checks. */
+#define GET_BYTE( X, i )                                \
+    ( ( ( X )[( i ) / ciL] >> ( ( ( i ) % ciL ) * 8 ) ) & 0xff )
+
 #endif /* MBEDTLS_BIGNUM_CORE_H */
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 07bd03892a..d9a1509d0c 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -10,17 +10,7 @@
 #if MBEDTLS_MPI_MAX_BITS > 792
 #define MPI_MAX_BITS_LARGER_THAN_792
 #endif
-
-#define ciL    (sizeof(mbedtls_mpi_uint))   /* chars in limb  */
-#define biL    (ciL << 3)                   /* bits  in limb  */
-
-/*
- * Convert between bits/chars and number of limbs
- * Divide first in order to avoid potential overflows
- */
-#define BITS_TO_LIMBS(i)  ( (i) / biL + ( (i) % biL != 0 ) )
-#define CHARS_TO_LIMBS(i) ( (i) / ciL + ( (i) % ciL != 0 ) )
-
+#
 /* Check the validity of the sign bit in an MPI object. Reject representations
  * that are not supported by the rest of the library and indicate a bug when
  * constructing the value. */