diff --git a/code/client/cl_http_windows.c b/code/client/cl_http_windows.c
index 9a6b6f75..d585521f 100644
--- a/code/client/cl_http_windows.c
+++ b/code/client/cl_http_windows.c
@@ -30,7 +30,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 static HINTERNET hInternet = NULL;
 static HINTERNET hUrl = NULL;
 
-static void DropIf(qboolean condition, const char *fmt, ...)
+static Q_PRINTF_FUNC(2, 3) void DropIf(qboolean condition, const char *fmt, ...)
 {
     char buffer[1024];
 
diff --git a/code/game/bg_lib.h b/code/game/bg_lib.h
index 924e92bb..31add8fe 100644
--- a/code/game/bg_lib.h
+++ b/code/game/bg_lib.h
@@ -94,7 +94,7 @@ int atoi( const char *string );
 int _atoi( const char **stringPtr );
 long strtol( const char *nptr, char **endptr, int base );
 
-int Q_vsnprintf( char *buffer, size_t length, const char *fmt, va_list argptr );
+int Q_vsnprintf( char *buffer, size_t length, const char *fmt, va_list argptr ) Q_PRINTF_FUNC(3, 0);
 
 int sscanf( const char *buffer, const char *fmt, ... ) Q_SCANF_FUNC(2, 3);
 
diff --git a/code/qcommon/q_shared.h b/code/qcommon/q_shared.h
index 262a9eb9..dc429ea8 100644
--- a/code/qcommon/q_shared.h
+++ b/code/qcommon/q_shared.h
@@ -108,7 +108,16 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #ifdef __GNUC__
 #define Q_UNUSED_VAR __attribute__((unused))
 #define Q_NO_RETURN __attribute__((noreturn))
+
+#ifdef __MINGW32__
+// For some reason MinGW wants both gnu_printf and ms_printf
+#define Q_PRINTF_FUNC(fmt, va) \
+	__attribute__((format(gnu_printf, fmt, va))) \
+	__attribute__((format(ms_printf, fmt, va)))
+#else
 #define Q_PRINTF_FUNC(fmt, va) __attribute__((format(printf, fmt, va)))
+#endif
+
 #define Q_SCANF_FUNC(fmt, va) __attribute__((format(scanf, fmt, va)))
 #define Q_ALIGN(x) __attribute__((aligned(x)))
 #else
@@ -168,7 +177,7 @@ typedef int intptr_t;
 #ifdef _WIN32
   // vsnprintf is ISO/IEC 9899:1999
   // abstracting this to make it portable
-  int Q_vsnprintf(char *str, size_t size, const char *format, va_list ap);
+  int Q_vsnprintf(char *str, size_t size, const char *format, va_list ap) Q_PRINTF_FUNC(3, 0);
 #else
   #define Q_vsnprintf vsnprintf
 #endif