diff --git a/src/kem/frodokem/pqclean_frodokem1344aes_clean/noise.c b/src/kem/frodokem/pqclean_frodokem1344aes_clean/noise.c
index d83162bcf..9205c9052 100644
--- a/src/kem/frodokem/pqclean_frodokem1344aes_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem1344aes_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM1344AES_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {
diff --git a/src/kem/frodokem/pqclean_frodokem1344shake_clean/noise.c b/src/kem/frodokem/pqclean_frodokem1344shake_clean/noise.c
index decce08a2..289d7aa36 100644
--- a/src/kem/frodokem/pqclean_frodokem1344shake_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem1344shake_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM1344SHAKE_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {
diff --git a/src/kem/frodokem/pqclean_frodokem640aes_clean/noise.c b/src/kem/frodokem/pqclean_frodokem640aes_clean/noise.c
index 2221219e0..44cd51be1 100644
--- a/src/kem/frodokem/pqclean_frodokem640aes_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem640aes_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM640AES_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {
diff --git a/src/kem/frodokem/pqclean_frodokem640shake_clean/noise.c b/src/kem/frodokem/pqclean_frodokem640shake_clean/noise.c
index 08c975d5e..32b6938d8 100644
--- a/src/kem/frodokem/pqclean_frodokem640shake_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem640shake_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM640SHAKE_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {
diff --git a/src/kem/frodokem/pqclean_frodokem976aes_clean/noise.c b/src/kem/frodokem/pqclean_frodokem976aes_clean/noise.c
index 45d868edc..8796e4d40 100644
--- a/src/kem/frodokem/pqclean_frodokem976aes_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem976aes_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM976AES_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {
diff --git a/src/kem/frodokem/pqclean_frodokem976shake_clean/noise.c b/src/kem/frodokem/pqclean_frodokem976shake_clean/noise.c
index b2b4f2dc9..e23892c84 100644
--- a/src/kem/frodokem/pqclean_frodokem976shake_clean/noise.c
+++ b/src/kem/frodokem/pqclean_frodokem976shake_clean/noise.c
@@ -16,12 +16,13 @@ void PQCLEAN_FRODOKEM976SHAKE_CLEAN_sample_n(uint16_t *s, size_t n) {
     // Fills vector s with n samples from the noise distribution which requires 16 bits to sample.
     // The distribution is specified by its CDF.
     // Input: pseudo-random values (2*n bytes) passed in s. The input is overwritten by the output.
-    unsigned int i, j;
+    size_t i;
+    unsigned int j;
 
     for (i = 0; i < n; ++i) {
-        uint8_t sample = 0;
+        uint16_t sample = 0;
         uint16_t prnd = s[i] >> 1;    // Drop the least significant bit
-        uint8_t sign = s[i] & 0x1;    // Pick the least significant bit
+        uint16_t sign = s[i] & 0x1;    // Pick the least significant bit
 
         // No need to compare with the last value.
         for (j = 0; j < (unsigned int)(CDF_TABLE_LEN - 1); j++) {