diff --git a/core/libs/prx/libc/src/FormattingWide.cpp b/core/libs/prx/libc/src/FormattingWide.cpp
index 0794a9db66..b4d7d13bf0 100644
--- a/core/libs/prx/libc/src/FormattingWide.cpp
+++ b/core/libs/prx/libc/src/FormattingWide.cpp
@@ -1,3 +1,4 @@
+#include <algorithm>
 #include "prx/libc/include/Api.hpp"
 #include <cerrno>
 #include <climits>
@@ -183,6 +184,8 @@ std::u16string FormatWide(const char16_t* format, VaList* source, bool secure =
             } else value = args.Next<unsigned long long>();
             if (conversion == u'o' && value == 0 && precision == 0 && spec.find('#') != std::string::npos)
                 spec = spec.substr(0, spec.find('.')) + ".1";
+            const auto flags = spec.begin() + static_cast<std::ptrdiff_t>(std::min(spec.find_first_not_of("-+ #0", 1), spec.size()));
+            spec.erase(std::remove_if(spec.begin() + 1, flags, [](char flag) { return flag == ' ' || flag == '+'; }), flags);
             AppendNumber(out, spec + "ll" + static_cast<char>(conversion), value);
         } else if (In(conversion, "aAeEfFgG")) {
             const char narrow = static_cast<char>(conversion);
diff --git a/core/libs/tests/GuestWideFormatting.cpp b/core/libs/tests/GuestWideFormatting.cpp
index 09fb72b4c8..5540d7ee60 100644
--- a/core/libs/tests/GuestWideFormatting.cpp
+++ b/core/libs/tests/GuestWideFormatting.cpp
@@ -138,6 +138,12 @@ static void CheckCount() {
     Require(Format(buffer, 16, u"a%n", nullCount) < 0, "vswprintf null %n argument");
 }
 
+static void CheckUnsignedSignFlags() {
+    char16_t buffer[32];
+    Require(swprintf_nid_postfix(buffer, 32, u"[% u|%+u|% lu|% 5u|%+x|% #o]", 7u, 7u, 7ul, 7u, 7u, 7u) == 18 &&
+        buffer == std::u16string(u"[7|7|7|    7|7|07]"), "unsigned conversions ignore the space and plus flags");
+}
+
 static void CheckGroupingFlag() {
     char16_t buffer[48];
     Require(swprintf_nid_postfix(buffer, 48, u"%'d|%'-6u|%'.2f|%'+05d|%'g", 1234567, 42u, 1234.5, 12, 1e6) == 34 &&
@@ -340,4 +346,5 @@ int main() {
     Check(u"%.1s", "\xf0\x9f\x98\x80x", u"");
     Check(u"%.3s", "\xf0\x9f\x98\x80x", u"\U0001f600x");
     CheckGroupingFlag();
+    CheckUnsignedSignFlags();
 }