diff --git a/dlls/kernel/tests/comm.c b/dlls/kernel/tests/comm.c
index 166bfb3906..b17c26e4c5 100644
--- a/dlls/kernel/tests/comm.c
+++ b/dlls/kernel/tests/comm.c
@@ -588,7 +588,7 @@ static void test_BuildCommDCB(void)
 {
 	char port_name[] = "COMx";
 	char port = 0;
-	int i;
+	unsigned int i;
 	char *ptr;
 
 	/* Some of these tests require a valid COM port.  This loop will try to find
diff --git a/dlls/kernel/tests/mailslot.c b/dlls/kernel/tests/mailslot.c
index 27f1d61b40..2e2513a1c5 100644
--- a/dlls/kernel/tests/mailslot.c
+++ b/dlls/kernel/tests/mailslot.c
@@ -81,13 +81,13 @@ static int mailslot_test()
     dwMax = dwNext = dwMsgCount = dwTimeout = 0;
     ok( GetMailslotInfo( hSlot, &dwMax, &dwNext, &dwMsgCount, &dwTimeout ),
            "getmailslotinfo failed\n");
-    ok( dwMax == -1, "dwMax incorrect\n");
+    ok( dwMax == ~0UL, "dwMax incorrect\n");
     ok( dwNext == MAILSLOT_NO_MESSAGE, "dwNext incorrect\n");
     }
     ok( dwMsgCount == 0, "dwMsgCount incorrect\n");
     todo_wine
     {
-    ok( dwTimeout == -1, "dwTimeout incorrect\n");
+    ok( dwTimeout == ~0UL, "dwTimeout incorrect\n");
     ok( GetMailslotInfo( hSlot, NULL, NULL, NULL, NULL ),
             "getmailslotinfo failed\n");
     ok( CloseHandle(hSlot), "failed to close mailslot\n");
diff --git a/dlls/kernel/tests/process.c b/dlls/kernel/tests/process.c
index 490c1b7fa0..7d962a9f9b 100644
--- a/dlls/kernel/tests/process.c
+++ b/dlls/kernel/tests/process.c
@@ -1082,17 +1082,17 @@ static void test_Console(void)
     okChildInt("StartupInfoA", "hStdInput", (DWORD)startup.hStdInput);
     okChildInt("StartupInfoA", "hStdOutput", (DWORD)startup.hStdOutput);
     okChildInt("StartupInfoA", "hStdError", (DWORD)startup.hStdError);
-    okChildInt("Console", "SizeX", sbi.dwSize.X);
-    okChildInt("Console", "SizeY", sbi.dwSize.Y);
-    okChildInt("Console", "CursorX", sbi.dwCursorPosition.X);
-    okChildInt("Console", "CursorY", sbi.dwCursorPosition.Y);
+    okChildInt("Console", "SizeX", (DWORD)sbi.dwSize.X);
+    okChildInt("Console", "SizeY", (DWORD)sbi.dwSize.Y);
+    okChildInt("Console", "CursorX", (DWORD)sbi.dwCursorPosition.X);
+    okChildInt("Console", "CursorY", (DWORD)sbi.dwCursorPosition.Y);
     okChildInt("Console", "Attributes", sbi.wAttributes);
-    okChildInt("Console", "winLeft", sbi.srWindow.Left);
-    okChildInt("Console", "winTop", sbi.srWindow.Top);
-    okChildInt("Console", "winRight", sbi.srWindow.Right);
-    okChildInt("Console", "winBottom", sbi.srWindow.Bottom);
-    okChildInt("Console", "maxWinWidth", sbi.dwMaximumWindowSize.X);
-    okChildInt("Console", "maxWinHeight", sbi.dwMaximumWindowSize.Y);
+    okChildInt("Console", "winLeft", (DWORD)sbi.srWindow.Left);
+    okChildInt("Console", "winTop", (DWORD)sbi.srWindow.Top);
+    okChildInt("Console", "winRight", (DWORD)sbi.srWindow.Right);
+    okChildInt("Console", "winBottom", (DWORD)sbi.srWindow.Bottom);
+    okChildInt("Console", "maxWinWidth", (DWORD)sbi.dwMaximumWindowSize.X);
+    okChildInt("Console", "maxWinHeight", (DWORD)sbi.dwMaximumWindowSize.Y);
     okChildInt("Console", "InputCP", cpIn);
     okChildInt("Console", "OutputCP", cpOut);
     okChildInt("Console", "InputMode", modeIn);
diff --git a/dlls/kernel/tests/thread.c b/dlls/kernel/tests/thread.c
index 5fae9682a9..e9b8b2d42a 100644
--- a/dlls/kernel/tests/thread.c
+++ b/dlls/kernel/tests/thread.c
@@ -246,8 +246,8 @@ VOID test_CreateThread_suspended()
 VOID test_SuspendThread()
 {
   HANDLE thread,access_thread;
-  DWORD threadId,exitCode;
-  int i,error;
+  DWORD threadId,exitCode,error;
+  int i;
 
   thread = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)threadFunc3,NULL,
                         0,&threadId);
@@ -273,9 +273,9 @@ VOID test_SuspendThread()
                            0,threadId);
     ok(access_thread!=NULL,"OpenThread returned an invalid handle\n");
     if (access_thread!=NULL) {
-      ok(SuspendThread(access_thread)==-1,
+      ok(SuspendThread(access_thread)==~0UL,
          "SuspendThread did not obey access restrictions\n");
-      ok(ResumeThread(access_thread)==-1,
+      ok(ResumeThread(access_thread)==~0UL,
          "ResumeThread did not obey access restrictions\n");
       ok(CloseHandle(access_thread)!=0,"CloseHandle Failed\n");
     }
@@ -292,7 +292,7 @@ VOID test_SuspendThread()
   }
   /* Trying to suspend a terminated thread should fail */
   error=SuspendThread(thread);
-  ok(error==0xffffffff, "wrong return code: %d\n", error);
+  ok(error==~0UL, "wrong return code: %ld\n", error);
   ok(GetLastError()==ERROR_ACCESS_DENIED || GetLastError()==ERROR_NO_MORE_ITEMS, "unexpected error code: %ld\n", GetLastError());
 
   ok(CloseHandle(thread)!=0,"CloseHandle Failed\n");