diff --git a/src/tools/mdbx_chk.c b/src/tools/mdbx_chk.c
index 7a93d70d..f1619965 100644
--- a/src/tools/mdbx_chk.c
+++ b/src/tools/mdbx_chk.c
@@ -18,7 +18,14 @@
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
 #pragma warning(disable : 4996) /* The POSIX name is deprecated... */
-#endif                          /* _MSC_VER */
+#if _MSC_VER == 1900
+/* LY: MSVC 2015 has buggy/inconsistent PRIuPTR/PRIxPTR macros and format-arg
+       checker for size_t typedef. */
+#pragma warning(disable : 4777) /* format string '%10u' requires an argument   \
+                                   of type 'unsigned int', but variadic        \
+                                   argument 1 has type 'std::size_t' */
+#endif
+#endif /* _MSC_VER (warnings) */
 
 #include "../bits.h"
 
@@ -203,7 +210,7 @@ static void problem_add(const char *object, uint64_t entry_number,
   }
 }
 
-static struct problem *problems_push() {
+static struct problem *problems_push(void) {
   struct problem *p = problems_list;
   problems_list = NULL;
   return p;
diff --git a/src/tools/mdbx_copy.c b/src/tools/mdbx_copy.c
index 2e384cac..ec0856ca 100644
--- a/src/tools/mdbx_copy.c
+++ b/src/tools/mdbx_copy.c
@@ -18,7 +18,14 @@
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
 #pragma warning(disable : 4996) /* The POSIX name is deprecated... */
-#endif                          /* _MSC_VER */
+#if _MSC_VER == 1900
+/* LY: MSVC 2015 has buggy/inconsistent PRIuPTR/PRIxPTR macros and format-arg
+       checker for size_t typedef. */
+#pragma warning(disable : 4777) /* format string '%10u' requires an argument   \
+                                   of type 'unsigned int', but variadic        \
+                                   argument 1 has type 'std::size_t' */
+#endif
+#endif /* _MSC_VER (warnings) */
 
 #include "../bits.h"
 
diff --git a/src/tools/mdbx_dump.c b/src/tools/mdbx_dump.c
index 71c300dd..19010c47 100644
--- a/src/tools/mdbx_dump.c
+++ b/src/tools/mdbx_dump.c
@@ -18,7 +18,14 @@
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
 #pragma warning(disable : 4996) /* The POSIX name is deprecated... */
-#endif                          /* _MSC_VER */
+#if _MSC_VER == 1900
+/* LY: MSVC 2015 has buggy/inconsistent PRIuPTR/PRIxPTR macros and format-arg
+       checker for size_t typedef. */
+#pragma warning(disable : 4777) /* format string '%10u' requires an argument   \
+                                   of type 'unsigned int', but variadic        \
+                                   argument 1 has type 'std::size_t' */
+#endif
+#endif /* _MSC_VER (warnings) */
 
 #include "../bits.h"
 #include <ctype.h>
diff --git a/src/tools/mdbx_load.c b/src/tools/mdbx_load.c
index 16180e86..0c20b1e7 100644
--- a/src/tools/mdbx_load.c
+++ b/src/tools/mdbx_load.c
@@ -18,7 +18,14 @@
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
 #pragma warning(disable : 4996) /* The POSIX name is deprecated... */
-#endif                          /* _MSC_VER */
+#if _MSC_VER == 1900
+/* LY: MSVC 2015 has buggy/inconsistent PRIuPTR/PRIxPTR macros and format-arg
+       checker for size_t typedef. */
+#pragma warning(disable : 4777) /* format string '%10u' requires an argument   \
+                                   of type 'unsigned int', but variadic        \
+                                   argument 1 has type 'std::size_t' */
+#endif
+#endif /* _MSC_VER (warnings) */
 
 #include "../bits.h"
 #include <ctype.h>
diff --git a/src/tools/mdbx_stat.c b/src/tools/mdbx_stat.c
index 7fbe924b..9b65d992 100644
--- a/src/tools/mdbx_stat.c
+++ b/src/tools/mdbx_stat.c
@@ -18,7 +18,14 @@
 #pragma warning(disable : 4464) /* relative include path contains '..' */
 #endif
 #pragma warning(disable : 4996) /* The POSIX name is deprecated... */
-#endif                          /* _MSC_VER */
+#if _MSC_VER == 1900
+/* LY: MSVC 2015 has buggy/inconsistent PRIuPTR/PRIxPTR macros and format-arg
+       checker for size_t typedef. */
+#pragma warning(disable : 4777) /* format string '%10u' requires an argument   \
+                                   of type 'unsigned int', but variadic        \
+                                   argument 1 has type 'std::size_t' */
+#endif
+#endif /* _MSC_VER (warnings) */
 
 #include "../bits.h"
 
diff --git a/src/tools/wingetopt.c b/src/tools/wingetopt.c
index 3762ecae..8059e5d9 100644
--- a/src/tools/wingetopt.c
+++ b/src/tools/wingetopt.c
@@ -20,9 +20,6 @@
 
 #define ERR(s, c)                                                              \
   if (opterr) {                                                                \
-    char errbuf[2];                                                            \
-    errbuf[0] = (char)c;                                                       \
-    errbuf[1] = '\n';                                                          \
     fputs(argv[0], stderr);                                                    \
     fputs(s, stderr);                                                          \
     fputc(c, stderr);                                                          \
@@ -38,13 +35,14 @@ int getopt(int argc, char *const argv[], const char *opts) {
   int c;
   char *cp;
 
-  if (sp == 1)
+  if (sp == 1) {
     if (optind >= argc || argv[optind][0] != '-' || argv[optind][1] == '\0')
       return EOF;
     else if (strcmp(argv[optind], "--") == 0) {
       optind++;
       return EOF;
     }
+  }
   optopt = c = argv[optind][sp];
   if (c == ':' || (cp = strchr(opts, c)) == NULL) {
     ERR(": illegal option -- ", c);