diff --git a/src/test/app/wasm_fixtures/fixtures.cpp b/src/test/app/wasm_fixtures/fixtures.cpp
index f5d4ac53ec..9e1783ef50 100644
--- a/src/test/app/wasm_fixtures/fixtures.cpp
+++ b/src/test/app/wasm_fixtures/fixtures.cpp
@@ -23,13 +23,11 @@ pushLeb128(std::vector<uint8_t>& buf, uint32_t val)
 }
 
 // Helper: append bytes from a C-style array to a vector
-// Uses a loop to avoid GCC false positive -Werror=stringop-overflow with insert()
 template <std::size_t N>
 void
 appendBytes(std::vector<uint8_t>& buf, uint8_t const (&arr)[N])
 {
-    for (std::size_t i = 0; i < N; ++i)
-        buf.push_back(arr[i]);
+    buf.insert(buf.end(), &arr[0], &arr[N]);
 }
 
 // Helper: append bytes from a vector to a vector
@@ -59,6 +57,7 @@ std::vector<uint8_t>
 generateCodeBlob(uint32_t num_instructions)
 {
     std::vector<uint8_t> wasm;
+    wasm.reserve(sizeof(WASM_HEADER) + sizeof(TYPE_EMPTY_FUNC) + sizeof(FUNC_TYPE0) + sizeof(EXPORT_FINISH));
     appendBytes(wasm, WASM_HEADER);
     appendBytes(wasm, TYPE_EMPTY_FUNC);
     appendBytes(wasm, FUNC_TYPE0);
@@ -82,6 +81,7 @@ std::vector<uint8_t>
 generateDataBlob(uint32_t data_size)
 {
     std::vector<uint8_t> wasm;
+    wasm.reserve(sizeof(WASM_HEADER) + sizeof(TYPE_EMPTY_FUNC) + sizeof(FUNC_TYPE0));
     appendBytes(wasm, WASM_HEADER);
     appendBytes(wasm, TYPE_EMPTY_FUNC);
     appendBytes(wasm, FUNC_TYPE0);
diff --git a/src/test/app/wasm_fixtures/fixtures.h b/src/test/app/wasm_fixtures/fixtures.h
index 7dcba6eb89..50ab5d653e 100644
--- a/src/test/app/wasm_fixtures/fixtures.h
+++ b/src/test/app/wasm_fixtures/fixtures.h
@@ -10,7 +10,7 @@
 namespace wasm_constants {
 
 // Magic + version header
-static constexpr uint8_t WASM_HEADER[] = {
+uint8_t const WASM_HEADER[] = {
     0x00,
     0x61,
     0x73,
@@ -22,31 +22,31 @@ static constexpr uint8_t WASM_HEADER[] = {
 };
 
 // Type section: () -> ()
-static constexpr uint8_t TYPE_EMPTY_FUNC[] = {0x01, 0x04, 0x01, 0x60, 0x00, 0x00};
+uint8_t const TYPE_EMPTY_FUNC[] = {0x01, 0x04, 0x01, 0x60, 0x00, 0x00};
 
 // Function section: one function using type 0
-static constexpr uint8_t FUNC_TYPE0[] = {0x03, 0x02, 0x01, 0x00};
+uint8_t const FUNC_TYPE0[] = {0x03, 0x02, 0x01, 0x00};
 
 // Export section: export func 0 as "finish"
-static constexpr uint8_t EXPORT_FINISH[] = {0x07, 0x0a, 0x01, 0x06, 'f', 'i', 'n', 'i', 's', 'h', 0x00, 0x00};
+uint8_t const EXPORT_FINISH[] = {0x07, 0x0a, 0x01, 0x06, 'f', 'i', 'n', 'i', 's', 'h', 0x00, 0x00};
 
 // Empty function body: 0 locals, end
-static constexpr uint8_t EMPTY_BODY[] = {0x00, 0x0b};
+uint8_t const EMPTY_BODY[] = {0x00, 0x0b};
 
 // Data segment offset: i32.const 0, end
-static constexpr uint8_t DATA_OFFSET_ZERO[] = {0x41, 0x00, 0x0b};
+uint8_t const DATA_OFFSET_ZERO[] = {0x41, 0x00, 0x0b};
 
 // Section IDs
-static constexpr uint8_t SECTION_MEMORY = 0x05;
-static constexpr uint8_t SECTION_CODE = 0x0a;
-static constexpr uint8_t SECTION_DATA = 0x0b;
+uint8_t const SECTION_MEMORY = 0x05;
+uint8_t const SECTION_CODE = 0x0a;
+uint8_t const SECTION_DATA = 0x0b;
 
 // Instructions
-static constexpr uint8_t INSTR_NOP = 0x01;
-static constexpr uint8_t INSTR_END = 0x0b;
+uint8_t const INSTR_NOP = 0x01;
+uint8_t const INSTR_END = 0x0b;
 
 // Fill byte for data section bloat
-static constexpr uint8_t DATA_FILL_BYTE = 0xEE;
+uint8_t const DATA_FILL_BYTE = 0xEE;
 
 // Generator for WASM module with large code section (many NOPs)
 std::vector<uint8_t>