diff --git a/tests/Gtest-nocalloc.c b/tests/Gtest-nocalloc.c
index cf1d3f7c..d16cf0bd 100644
--- a/tests/Gtest-nocalloc.c
+++ b/tests/Gtest-nocalloc.c
@@ -111,7 +111,7 @@ foo1 (void)
 }
 
 int
-main (int argc, char **argv)
+main (void)
 {
   int i, num_errors;
 
diff --git a/tests/Gtest-nomalloc.c b/tests/Gtest-nomalloc.c
index 70faa368..db778546 100644
--- a/tests/Gtest-nomalloc.c
+++ b/tests/Gtest-nomalloc.c
@@ -101,7 +101,7 @@ foo1 ()
 }
 
 int
-main (int argc, char **argv)
+main (void)
 {
   foo1();
 
diff --git a/tests/mapper.c b/tests/mapper.c
index 6edce711..e84697bf 100644
--- a/tests/mapper.c
+++ b/tests/mapper.c
@@ -41,7 +41,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #endif
 
 int
-main (int argc, char **argv)
+main (void)
 {
   long n = 0;
 
diff --git a/tests/test-ptrace.c b/tests/test-ptrace.c
index 7d762007..17a1b611 100644
--- a/tests/test-ptrace.c
+++ b/tests/test-ptrace.c
@@ -28,7 +28,7 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #ifdef HAVE_TTRACE
 
 int
-main (int argc, char **argv)
+main (void)
 {
   printf ("FAILURE: ttrace() not supported yet\n");
   return -1;
@@ -73,7 +73,7 @@ static struct UPT_info *ui;
 static int killed;
 
 void
-do_backtrace (pid_t target_pid)
+do_backtrace (void)
 {
   unw_word_t ip, sp, start_ip = 0, off;
   int n = 0, ret;
@@ -301,7 +301,7 @@ main (int argc, char **argv)
 #endif
 	  else
 	    {
-	      do_backtrace (target_pid);
+	      do_backtrace ();
 #if HAVE_DECL_PTRACE_SINGLESTEP
 	      ptrace (PTRACE_SINGLESTEP, target_pid, 0, pending_sig);
 #elif HAVE_DECL_PT_STEP
@@ -314,7 +314,7 @@ main (int argc, char **argv)
 
 	case SYSCALL:
 	  if (!state)
-	    do_backtrace (target_pid);
+	    do_backtrace ();
 	  state ^= 1;
 #if HAVE_DECL_PTRACE_SYSCALL
 	  ptrace (PTRACE_SYSCALL, target_pid, 0, pending_sig);
@@ -326,7 +326,7 @@ main (int argc, char **argv)
 	  break;
 
 	case INSTRUCTION:
-	  do_backtrace (target_pid);
+	  do_backtrace ();
 #if HAVE_DECL_PTRACE_SINGLESTEP
 	      ptrace (PTRACE_SINGLESTEP, target_pid, 0, pending_sig);
 #elif HAVE_DECL_PT_STEP
diff --git a/tests/test-varargs.c b/tests/test-varargs.c
index b712f5db..9366461e 100644
--- a/tests/test-varargs.c
+++ b/tests/test-varargs.c
@@ -45,7 +45,7 @@ a (int d, ...)
 }
 
 int
-main (int argc, char **argv)
+main (void)
 {
   a (5, 3, 4, 5, 6);
   return 0;