diff --git a/lib/src/phy/fec/convolutional/viterbi37_avx2.c b/lib/src/phy/fec/convolutional/viterbi37_avx2.c
index 0749bfdf4..48e069831 100644
--- a/lib/src/phy/fec/convolutional/viterbi37_avx2.c
+++ b/lib/src/phy/fec/convolutional/viterbi37_avx2.c
@@ -11,6 +11,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 //#define DEBUG
 
diff --git a/lib/src/phy/fec/convolutional/viterbi37_avx2_16bit.c b/lib/src/phy/fec/convolutional/viterbi37_avx2_16bit.c
index 6d143dbb1..56c182d9f 100644
--- a/lib/src/phy/fec/convolutional/viterbi37_avx2_16bit.c
+++ b/lib/src/phy/fec/convolutional/viterbi37_avx2_16bit.c
@@ -11,6 +11,8 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <strings.h>
 
 //#define DEBUG
 
diff --git a/lib/src/phy/fec/convolutional/viterbi37_port.c b/lib/src/phy/fec/convolutional/viterbi37_port.c
index 122dfd188..b1698df20 100644
--- a/lib/src/phy/fec/convolutional/viterbi37_port.c
+++ b/lib/src/phy/fec/convolutional/viterbi37_port.c
@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <strings.h>
 
 #include "parity.h"
 #include "viterbi37.h"
diff --git a/lib/src/phy/fec/convolutional/viterbi37_sse.c b/lib/src/phy/fec/convolutional/viterbi37_sse.c
index 2730c8c01..3e49ad092 100644
--- a/lib/src/phy/fec/convolutional/viterbi37_sse.c
+++ b/lib/src/phy/fec/convolutional/viterbi37_sse.c
@@ -11,6 +11,7 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 //#define DEBUG
 
diff --git a/lib/src/phy/fec/polar/polar_interleaver.c b/lib/src/phy/fec/polar/polar_interleaver.c
index 27475ae3c..66b24e4e8 100644
--- a/lib/src/phy/fec/polar/polar_interleaver.c
+++ b/lib/src/phy/fec/polar/polar_interleaver.c
@@ -14,6 +14,7 @@
 #include "srsran/phy/utils/vector.h"
 #include <memory.h>
 #include <stddef.h>
+#include <string.h>
 
 // Table 5.3.1.1-1: Interleaving pattern
 static const uint16_t polar_interleaver_pattern[SRSRAN_POLAR_INTERLEAVER_K_MAX_IL] = {
diff --git a/lib/src/phy/utils/mat.c b/lib/src/phy/utils/mat.c
index 660523063..5c50d8b21 100644
--- a/lib/src/phy/utils/mat.c
+++ b/lib/src/phy/utils/mat.c
@@ -16,6 +16,7 @@
 #include <srsran/phy/utils/vector.h>
 #include <srsran/phy/utils/vector_simd.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "srsran/phy/utils/mat.h"