diff --git a/lib/common/cmp_support.c b/lib/common/cmp_support.c
index 464acad84d1b45aa14494ceaa6023db9922ee178..1beaec2a66327e7cafae90a2885d36e3ce7e7b13 100644
--- a/lib/common/cmp_support.c
+++ b/lib/common/cmp_support.c
@@ -349,21 +349,6 @@ unsigned int cmp_bit_to_byte(unsigned int cmp_size_bit)
 }
 
 
-/**
- * @brief calculate the need bytes to hold a bitstream
- * @note we round up the result to multiples of 4 bytes
- *
- * @param cmp_size_bit	compressed data size, measured in bits
- *
- * @returns the size in bytes to store the hole bitstream
- */
-
-unsigned int cmp_bit_to_4byte(unsigned int cmp_size_bit)
-{
-	return (cmp_bit_to_byte(cmp_size_bit) + 3) & ~0x3UL;
-}
-
-
 /**
  * @brief check if the compression data type, compression mode, model value and
  *	the lossy rounding parameters are invalid for a RDCU or ICU compression
diff --git a/lib/common/cmp_support.h b/lib/common/cmp_support.h
index fd90ce82baf5c373eedc5dabbe8b0ba5e6c445f8..11eec690589b281366ac2edf087064ebe44a8a1d 100644
--- a/lib/common/cmp_support.h
+++ b/lib/common/cmp_support.h
@@ -333,9 +333,7 @@ struct fx_cob_par {
 
 int is_a_pow_of_2(unsigned int v);
 unsigned int ilog_2(uint32_t x);
-
 unsigned int cmp_bit_to_byte(unsigned int cmp_size_bit);
-unsigned int cmp_bit_to_4byte(unsigned int cmp_size_bit);
 
 int cmp_cfg_icu_is_invalid(const struct cmp_cfg *cfg);
 int cmp_cfg_gen_par_is_invalid(const struct cmp_cfg *cfg);
diff --git a/lib/rdcu_compress/cmp_rdcu.c b/lib/rdcu_compress/cmp_rdcu.c
index 9635570f45741b3f72efa9ae3acb374010d73ced..d1e54e726a27d2e0f1f14799221caabeb2471c49 100644
--- a/lib/rdcu_compress/cmp_rdcu.c
+++ b/lib/rdcu_compress/cmp_rdcu.c
@@ -406,6 +406,21 @@ int rdcu_read_cmp_info(struct cmp_info *info)
 }
 
 
+/**
+ * @brief calculate the need bytes to hold a bitstream
+ * @note we round up the result to multiples of 4 bytes
+ *
+ * @param cmp_size_bit	compressed data size, measured in bits
+ *
+ * @returns the size in bytes to store the hole bitstream
+ */
+
+static unsigned int cmp_bit_to_4byte(unsigned int cmp_size_bit)
+{
+	return (cmp_bit_to_byte(cmp_size_bit) + 3) & ~0x3UL;
+}
+
+
 /**
  * @brief read the compressed bitstream from the RDCU SRAM
  *