diff --git a/client/emv/emv_pk.c b/client/emv/emv_pk.c
index 7b8cdd233..f78997f5a 100644
--- a/client/emv/emv_pk.c
+++ b/client/emv/emv_pk.c
@@ -43,7 +43,7 @@
 static ssize_t emv_pk_read_bin(char *buf, unsigned char *bin, size_t size, size_t *read) {
     size_t left = size;
     char *p = buf;
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     while (left > 0) {
@@ -70,7 +70,7 @@ static ssize_t emv_pk_read_bin(char *buf, unsigned char *bin, size_t size, size_
             return -(p - buf);
     }
 
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     p--;
@@ -85,7 +85,7 @@ static ssize_t emv_pk_read_ymv(char *buf, unsigned *ymv) {
 
     *ymv = 0;
 
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     for (i = 0; i < 3; i++) {
@@ -101,7 +101,7 @@ static ssize_t emv_pk_read_ymv(char *buf, unsigned *ymv) {
         temp[i] = (c1 * 16 + c2);
     }
 
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     p--;
@@ -116,7 +116,7 @@ static ssize_t emv_pk_read_ymv(char *buf, unsigned *ymv) {
 
 static ssize_t emv_pk_read_string(char *buf, char *str, size_t size) {
     char *p = buf;
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     while (size > 1) {
@@ -132,7 +132,7 @@ static ssize_t emv_pk_read_string(char *buf, char *str, size_t size) {
 
     *str = 0;
 
-    while (*p != 0 && *p == ' ')
+    while (p != NULL && *p == ' ')
         p++;
 
     p--;