diff --git a/tests/libtest/first.c b/tests/libtest/first.c
index e2e1bfaed..a58755c41 100644
--- a/tests/libtest/first.c
+++ b/tests/libtest/first.c
@@ -34,8 +34,8 @@ int select_test (int num_fds, fd_set *rd, fd_set *wr, fd_set *exc,
   return select(num_fds, rd, wr, exc, tv);
 }
 
-char *arg2=NULL;
-char *arg3=NULL;
+char *libtest_arg2=NULL;
+char *libtest_arg3=NULL;
 int test_argc;
 char **test_argv;
 
@@ -73,10 +73,10 @@ int main(int argc, char **argv)
   test_argv = argv;
 
   if(argc>2)
-    arg2=argv[2];
+    libtest_arg2=argv[2];
 
   if(argc>3)
-    arg3=argv[3];
+    libtest_arg3=argv[3];
 
   URL = argv[1]; /* provide this to the rest */
 
diff --git a/tests/libtest/lib503.c b/tests/libtest/lib503.c
index 8294e8ccb..327402242 100644
--- a/tests/libtest/lib503.c
+++ b/tests/libtest/lib503.c
@@ -48,7 +48,7 @@ int test(char *URL)
     return TEST_ERR_MAJOR_BAD;
   }
 
-  curl_easy_setopt(c, CURLOPT_PROXY, arg2); /* set in first.c */
+  curl_easy_setopt(c, CURLOPT_PROXY, libtest_arg2); /* set in first.c */
   curl_easy_setopt(c, CURLOPT_URL, URL);
   curl_easy_setopt(c, CURLOPT_USERPWD, "test:ing");
   curl_easy_setopt(c, CURLOPT_PROXYUSERPWD, "test:ing");
diff --git a/tests/libtest/lib504.c b/tests/libtest/lib504.c
index 6bfbe4dde..a6e988657 100644
--- a/tests/libtest/lib504.c
+++ b/tests/libtest/lib504.c
@@ -53,7 +53,7 @@ int test(char *URL)
 
   /* the point here being that there must not run anything on the given
      proxy port */
-  curl_easy_setopt(c, CURLOPT_PROXY, arg2);
+  curl_easy_setopt(c, CURLOPT_PROXY, libtest_arg2);
   curl_easy_setopt(c, CURLOPT_URL, URL);
   curl_easy_setopt(c, CURLOPT_VERBOSE, 1);
 
diff --git a/tests/libtest/lib505.c b/tests/libtest/lib505.c
index 098e8f9e0..d2698faa9 100644
--- a/tests/libtest/lib505.c
+++ b/tests/libtest/lib505.c
@@ -49,36 +49,36 @@ int test(char *URL)
   const char *buf_1 = "RNFR 505";
   const char *buf_2 = "RNTO 505-forreal";
 
-  if (!arg2) {
+  if (!libtest_arg2) {
     fprintf(stderr, "Usage: <url> <file-to-upload>\n");
     return -1;
   }
 
   /* get the file size of the local file */
-  hd = stat(arg2, &file_info);
+  hd = stat(libtest_arg2, &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
     error = ERRNO;
     fprintf(stderr, "stat() failed with error: %d %s\n",
             error, strerror(error));
-    fprintf(stderr, "WARNING: cannot open file %s\n", arg2);
+    fprintf(stderr, "WARNING: cannot open file %s\n", libtest_arg2);
     return -1;
   }
 
   if(! file_info.st_size) {
-    fprintf(stderr, "WARNING: file %s has no size!\n", arg2);
+    fprintf(stderr, "WARNING: file %s has no size!\n", libtest_arg2);
     return -4;
   }
 
   /* get a FILE * of the same file, could also be made with
      fdopen() from the previous descriptor, but hey this is just
      an example! */
-  hd_src = fopen(arg2, "rb");
+  hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
     error = ERRNO;
     fprintf(stderr, "fopen() failed with error: %d %s\n",
             error, strerror(error));
-    fprintf(stderr, "Error opening file: %s\n", arg2);
+    fprintf(stderr, "Error opening file: %s\n", libtest_arg2);
     return -2; /* if this happens things are major weird */
   }
 
diff --git a/tests/libtest/lib509.c b/tests/libtest/lib509.c
index 34749e2d3..f4dadce73 100644
--- a/tests/libtest/lib509.c
+++ b/tests/libtest/lib509.c
@@ -206,8 +206,8 @@ int test(char *URL)
   char ml_timedout = FALSE;
   char mp_timedout = FALSE;
 
-  if(arg2) {
-    portnum = atoi(arg2);
+  if(libtest_arg2) {
+    portnum = atoi(libtest_arg2);
   }
 
   if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
diff --git a/tests/libtest/lib521.c b/tests/libtest/lib521.c
index 088534955..7301e3cd1 100644
--- a/tests/libtest/lib521.c
+++ b/tests/libtest/lib521.c
@@ -27,7 +27,7 @@ int test(char *URL)
   }
 
   curl_easy_setopt(curl, CURLOPT_URL, URL);
-  curl_easy_setopt(curl, CURLOPT_PORT, atoi(arg2));
+  curl_easy_setopt(curl, CURLOPT_PORT, atoi(libtest_arg2));
   curl_easy_setopt(curl, CURLOPT_USERPWD, "xxx:yyy");
   curl_easy_setopt(curl, CURLOPT_VERBOSE, TRUE);
 
diff --git a/tests/libtest/lib523.c b/tests/libtest/lib523.c
index 6ddfc947f..c6c8e2e31 100644
--- a/tests/libtest/lib523.c
+++ b/tests/libtest/lib523.c
@@ -26,7 +26,7 @@ int test(char *URL)
     return TEST_ERR_MAJOR_BAD;
   }
 
-  curl_easy_setopt(curl, CURLOPT_PROXY, arg2);
+  curl_easy_setopt(curl, CURLOPT_PROXY, libtest_arg2);
   curl_easy_setopt(curl, CURLOPT_URL, URL);
   curl_easy_setopt(curl, CURLOPT_PORT, 19999);
   curl_easy_setopt(curl, CURLOPT_USERPWD, "xxx:yyy");
diff --git a/tests/libtest/lib525.c b/tests/libtest/lib525.c
index b60328ba1..222f8c278 100644
--- a/tests/libtest/lib525.c
+++ b/tests/libtest/lib525.c
@@ -35,25 +35,25 @@ int test(char *URL)
   char ml_timedout = FALSE;
   char mp_timedout = FALSE;
 
-  if (!arg2) {
+  if (!libtest_arg2) {
     fprintf(stderr, "Usage: lib525 [url] [uploadfile]\n");
     return -1;
   }
 
   /* get the file size of the local file */
-  hd = open(arg2, O_RDONLY) ;
+  hd = open(libtest_arg2, O_RDONLY) ;
   fstat(hd, &file_info);
   close(hd) ;
 
   /* get a FILE * of the same file, could also be made with
      fdopen() from the previous descriptor, but hey this is just
      an example! */
-  hd_src = fopen(arg2, "rb");
+  hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
     error = ERRNO;
     fprintf(stderr, "fopen() failed with error: %d %s\n",
             error, strerror(error));
-    fprintf(stderr, "Error opening file: %s\n", arg2);
+    fprintf(stderr, "Error opening file: %s\n", libtest_arg2);
     return TEST_ERR_MAJOR_BAD;
   }
 
diff --git a/tests/libtest/lib533.c b/tests/libtest/lib533.c
index ee5f78f28..71c43c2ca 100644
--- a/tests/libtest/lib533.c
+++ b/tests/libtest/lib533.c
@@ -102,7 +102,7 @@ int test(char *URL)
           /* make us re-use the same handle all the time, and try resetting
              the handle first too */
           curl_easy_reset(curl);
-          curl_easy_setopt(curl, CURLOPT_URL, arg2);
+          curl_easy_setopt(curl, CURLOPT_URL, libtest_arg2);
           curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);
           curl_easy_setopt(curl, CURLOPT_FAILONERROR, 1);
 
diff --git a/tests/libtest/lib536.c b/tests/libtest/lib536.c
index 6b0a6a223..29e599fcd 100644
--- a/tests/libtest/lib536.c
+++ b/tests/libtest/lib536.c
@@ -108,7 +108,7 @@ int test(char *URL)
   curl_easy_reset(easy);
 
   curl_easy_setopt(easy, CURLOPT_FAILONERROR, 1);
-  curl_easy_setopt(easy, CURLOPT_URL, arg2);
+  curl_easy_setopt(easy, CURLOPT_URL, libtest_arg2);
 
   if (curl_multi_add_handle(multi, easy) != CURLM_OK) {
     printf("curl_multi_add_handle() 2 failed\n");
diff --git a/tests/libtest/lib540.c b/tests/libtest/lib540.c
index c5c48c471..4560eb815 100644
--- a/tests/libtest/lib540.c
+++ b/tests/libtest/lib540.c
@@ -18,8 +18,8 @@
 
 #include "test.h"
 
-#define PROXY arg2
-#define PROXYUSERPWD arg3
+#define PROXY libtest_arg2
+#define PROXYUSERPWD libtest_arg3
 #define HOST test_argv[4]
 
 static void init(CURLM *cm, const char* url, const char* userpwd,
diff --git a/tests/libtest/lib541.c b/tests/libtest/lib541.c
index 3ab1e2595..71d2e38ed 100644
--- a/tests/libtest/lib541.c
+++ b/tests/libtest/lib541.c
@@ -41,36 +41,36 @@ int test(char *URL)
   struct_stat file_info;
   int error;
 
-  if (!arg2) {
+  if (!libtest_arg2) {
     fprintf(stderr, "Usage: <url> <file-to-upload>\n");
     return -1;
   }
 
   /* get the file size of the local file */
-  hd = stat(arg2, &file_info);
+  hd = stat(libtest_arg2, &file_info);
   if(hd == -1) {
     /* can't open file, bail out */
     error = ERRNO;
     fprintf(stderr, "stat() failed with error: %d %s\n",
             error, strerror(error));
-    fprintf(stderr, "WARNING: cannot open file %s\n", arg2);
+    fprintf(stderr, "WARNING: cannot open file %s\n", libtest_arg2);
     return -1;
   }
 
   if(! file_info.st_size) {
-    fprintf(stderr, "WARNING: file %s has no size!\n", arg2);
+    fprintf(stderr, "WARNING: file %s has no size!\n", libtest_arg2);
     return -4;
   }
 
   /* get a FILE * of the same file, could also be made with
      fdopen() from the previous descriptor, but hey this is just
      an example! */
-  hd_src = fopen(arg2, "rb");
+  hd_src = fopen(libtest_arg2, "rb");
   if(NULL == hd_src) {
     error = ERRNO;
     fprintf(stderr, "fopen() failed with error: %d %s\n",
             error, strerror(error));
-    fprintf(stderr, "Error opening file: %s\n", arg2);
+    fprintf(stderr, "Error opening file: %s\n", libtest_arg2);
     return -2; /* if this happens things are major weird */
   }
 
diff --git a/tests/libtest/test.h b/tests/libtest/test.h
index 5cbdcede4..50c3a7959 100644
--- a/tests/libtest/test.h
+++ b/tests/libtest/test.h
@@ -36,8 +36,8 @@
 #define TEST_ERR_MAJOR_BAD     100
 #define TEST_ERR_RUNS_FOREVER   99
 
-extern char *arg2; /* set by first.c to the argv[2] or NULL */
-extern char *arg3; /* set by first.c to the argv[3] or NULL */
+extern char *libtest_arg2; /* set by first.c to the argv[2] or NULL */
+extern char *libtest_arg3; /* set by first.c to the argv[3] or NULL */
 
 /* argc and argv as passed in to the main() function */
 extern int test_argc;