diff --git a/test/fuzzing/chrono_duration.cpp b/test/fuzzing/chrono_duration.cpp
index 2b5410f4d931..c4bd1e76a65e 100644
--- a/test/fuzzing/chrono_duration.cpp
+++ b/test/fuzzing/chrono_duration.cpp
@@ -20,7 +20,7 @@ void invoke_inner(fmt::string_view formatstring, const Item item) {
     fmt::memory_buffer buf;
     fmt::format_to(buf, formatstring, value);
 #endif
-  } catch (std::exception& e) {
+  } catch (std::exception& /*e*/) {
   }
 }
 
@@ -36,12 +36,7 @@ void invoke_outer(const uint8_t* Data, std::size_t Size, const int scaling) {
     return;
   }
 
-#if __cplusplus >= 201402L
-  static_assert(std::is_trivially_copyable<Item>::value,
-                "Item must be blittable");
-#endif
-  Item item{};
-  std::memcpy(&item, Data, N);
+  const Item item = fmt_fuzzer::assignFromBuf<Item>(Data);
 
   // fast forward
   Data += Nfixed;
@@ -49,7 +44,7 @@ void invoke_outer(const uint8_t* Data, std::size_t Size, const int scaling) {
 
   // Data is already allocated separately in libFuzzer so reading past
   // the end will most likely be detected anyway
-  const auto formatstring = fmt::string_view((const char*)Data, Size);
+  const auto formatstring = fmt::string_view(fmt_fuzzer::as_chars(Data), Size);
 
   // doit_impl<Item,std::yocto>(buf.data(),item);
   // doit_impl<Item,std::zepto>(buf.data(),item);
diff --git a/test/fuzzing/fuzzer_common.h b/test/fuzzing/fuzzer_common.h
index 2e64bcc765f7..618ef17e2081 100644
--- a/test/fuzzing/fuzzer_common.h
+++ b/test/fuzzing/fuzzer_common.h
@@ -1,5 +1,8 @@
 #ifndef FUZZER_COMMON_H
 #define FUZZER_COMMON_H
+
+#include <cstring> // memcpy
+
 // Copyright (c) 2019, Paul Dreik
 // License: see LICENSE.rst in the fmt root directory
 
@@ -34,7 +37,33 @@ namespace fmt_fuzzer {
 }
 #endif
 
+namespace fmt_fuzzer {
+template <typename T>
+inline const char* as_chars(const T* data) {
+    return static_cast<const char*>(static_cast<const void*>(data));
+}
+template <typename T>
+inline const std::uint8_t* as_bytes(const T* data) {
+    return static_cast<const std::uint8_t*>(static_cast<const void*>(data));
+}
+
 
+template <class Item>
+inline Item assignFromBuf(const uint8_t* Data) {
+#if __cplusplus >= 201402L
+  static_assert(std::is_trivially_copyable<Item>::value,
+                "Item must be blittable");
+#endif
+  Item item{};
+  std::memcpy(&item, Data, sizeof(Item));
+  return item;
+}
+
+template <> inline bool assignFromBuf<bool>(const uint8_t* Data) {
+  return !!Data[0];
+}
+
+}
 
 
 #endif // FUZZER_COMMON_H
diff --git a/test/fuzzing/main.cpp b/test/fuzzing/main.cpp
index 37294855d4e1..faff78855618 100644
--- a/test/fuzzing/main.cpp
+++ b/test/fuzzing/main.cpp
@@ -4,6 +4,7 @@
 #  include <fstream>
 #  include <sstream>
 #  include <vector>
+#include "fuzzer_common.h"
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size);
 int main(int argc, char* argv[]) {
   for (int i = 1; i < argc; ++i) {
@@ -11,11 +12,12 @@ int main(int argc, char* argv[]) {
     assert(in);
     in.seekg(0, std::ios_base::end);
     const auto pos = in.tellg();
+    assert(pos>=0);
     in.seekg(0, std::ios_base::beg);
-    std::vector<char> buf(pos);
-    in.read(buf.data(), buf.size());
+    std::vector<char> buf(static_cast<std::size_t>(pos));
+    in.read(buf.data(), static_cast<long>(buf.size()));
     assert(in.gcount() == pos);
-    LLVMFuzzerTestOneInput((const uint8_t*)buf.data(), buf.size());
+    LLVMFuzzerTestOneInput(fmt_fuzzer::as_bytes(buf.data()), buf.size());
   }
 }
 #endif
diff --git a/test/fuzzing/named_arg.cpp b/test/fuzzing/named_arg.cpp
index 6db00d2aaba5..247f9495d418 100644
--- a/test/fuzzing/named_arg.cpp
+++ b/test/fuzzing/named_arg.cpp
@@ -10,18 +10,14 @@
 #include "fuzzer_common.h"
 
 template <typename Item1>
-void invoke_fmt(const uint8_t* Data, std::size_t Size, int argsize) {
+void invoke_fmt(const uint8_t* Data, std::size_t Size, unsigned int argsize) {
   constexpr auto N1 = sizeof(Item1);
   static_assert (N1<=fmt_fuzzer::Nfixed,"Nfixed too small");
   if (Size <= fmt_fuzzer::Nfixed) {
     return;
   }
-  Item1 item1{};
-  if /*constexpr*/ (std::is_same<Item1, bool>::value) {
-    item1 = !!Data[0];
-  } else {
-    std::memcpy(&item1, Data, N1);
-  }
+  const Item1 item1 = fmt_fuzzer::assignFromBuf<Item1>(Data);
+
   Data += fmt_fuzzer::Nfixed;
   Size -= fmt_fuzzer::Nfixed;
 
@@ -110,7 +106,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size) {
 
   // switch types depending on the first byte of the input
   const auto first = Data[0] & 0x0F;
-  const auto second = (Data[0] & 0xF0) >> 4;
+  const unsigned int second = (Data[0] & 0xF0) >> 4;
   Data++;
   Size--;
 
@@ -120,7 +116,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size) {
 
   try {
     invoke(first, outerfcn);
-  } catch (std::exception& e) {
+  } catch (std::exception& /*e*/) {
   }
   return 0;
 }
diff --git a/test/fuzzing/one_arg.cpp b/test/fuzzing/one_arg.cpp
index 36b2cd449bf1..b45f25123305 100644
--- a/test/fuzzing/one_arg.cpp
+++ b/test/fuzzing/one_arg.cpp
@@ -19,12 +19,7 @@ void invoke_fmt(const uint8_t* Data, std::size_t Size) {
   if (Size <= Nfixed) {
     return;
   }
-  Item item{};
-  if /*constexpr*/ (std::is_same<Item, bool>::value) {
-    item = !!Data[0];
-  } else {
-    std::memcpy(&item, Data, N);
-  }
+  const Item item = fmt_fuzzer::assignFromBuf<Item>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 
@@ -52,8 +47,7 @@ void invoke_fmt_time(const uint8_t* Data, std::size_t Size) {
   if (Size <= Nfixed) {
     return;
   }
-  Item item{};
-  std::memcpy(&item, Data, N);
+  const Item item = fmt_fuzzer::assignFromBuf<Item>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 #if FMT_FUZZ_SEPARATE_ALLOCATION
@@ -131,7 +125,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size) {
     default:
       break;
     }
-  } catch (std::exception& e) {
+  } catch (std::exception& /*e*/) {
   }
   return 0;
 }
diff --git a/test/fuzzing/sprintf.cpp b/test/fuzzing/sprintf.cpp
index 312aa4fd2984..7dd022213fd8 100644
--- a/test/fuzzing/sprintf.cpp
+++ b/test/fuzzing/sprintf.cpp
@@ -9,17 +9,6 @@
 
 using fmt_fuzzer::Nfixed;
 
-template <class Item>
-Item assignFromBuf(const uint8_t* Data, std::size_t Size) {
-  Item item{};
-  std::memcpy(&item, Data, sizeof(Item));
-  return item;
-}
-
-template <> bool assignFromBuf<bool>(const uint8_t* Data, std::size_t Size) {
-  return !!Data[0];
-}
-
 template <typename Item1, typename Item2>
 void invoke_fmt(const uint8_t* Data, std::size_t Size) {
   constexpr auto N1 = sizeof(Item1);
@@ -29,15 +18,15 @@ void invoke_fmt(const uint8_t* Data, std::size_t Size) {
   if (Size <= Nfixed + Nfixed) {
     return;
   }
-  Item1 item1 = assignFromBuf<Item1>(Data, Size);
+  Item1 item1 = fmt_fuzzer::assignFromBuf<Item1>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 
-  Item2 item2 = assignFromBuf<Item2>(Data, Size);
+  Item2 item2 = fmt_fuzzer::assignFromBuf<Item2>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 
-  auto fmtstring = fmt::string_view((const char*)Data, Size);
+  auto fmtstring = fmt::string_view(fmt_fuzzer::as_chars(Data), Size);
 
 #if FMT_FUZZ_FORMAT_TO_STRING
   std::string message = fmt::format(fmtstring, item1, item2);
@@ -121,7 +110,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size) {
 
   try {
     invoke(first, outer);
-  } catch (std::exception& e) {
+  } catch (std::exception& /*e*/) {
   }
   return 0;
 }
diff --git a/test/fuzzing/two_args.cpp b/test/fuzzing/two_args.cpp
index a61201a94ee2..8cfc4be89f19 100644
--- a/test/fuzzing/two_args.cpp
+++ b/test/fuzzing/two_args.cpp
@@ -18,25 +18,15 @@ void invoke_fmt(const uint8_t* Data, std::size_t Size) {
   if (Size <= Nfixed + Nfixed) {
     return;
   }
-  Item1 item1{};
-  if /*constexpr*/ (std::is_same<Item1, bool>::value) {
-    item1 = !!Data[0];
-  } else {
-    std::memcpy(&item1, Data, N1);
-  }
+  const Item1 item1=fmt_fuzzer::assignFromBuf<Item1>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 
-  Item2 item2{};
-  if /*constexpr*/ (std::is_same<Item2, bool>::value) {
-    item2 = !!Data[0];
-  } else {
-    std::memcpy(&item2, Data, N2);
-  }
+  const Item2 item2=fmt_fuzzer::assignFromBuf<Item2>(Data);
   Data += Nfixed;
   Size -= Nfixed;
 
-  auto fmtstring = fmt::string_view((const char*)Data, Size);
+  auto fmtstring = fmt::string_view(fmt_fuzzer::as_chars(Data), Size);
 
 #if FMT_FUZZ_FORMAT_TO_STRING
   std::string message = fmt::format(fmtstring, item1, item2);
@@ -116,7 +106,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* Data, std::size_t Size) {
 
   try {
     invoke(first, outer);
-  } catch (std::exception& e) {
+  } catch (std::exception& /*e*/) {
   }
   return 0;
 }