diff --git a/srcpkgs/mozjs78/patches/build-non-jit-32bit.patch b/srcpkgs/mozjs78/patches/build-non-jit-32bit.patch
new file mode 100644
index 0000000000..f2cf04d79a
--- /dev/null
+++ b/srcpkgs/mozjs78/patches/build-non-jit-32bit.patch
@@ -0,0 +1,14 @@
+On 32-bit systems without JIT, the GC doesn't like 4-byte alignment,
+so enforce a stricter one.
+
+--- a/js/src/jit/none/MacroAssembler-none.h
++++ b/js/src/jit/none/MacroAssembler-none.h
+@@ -100,7 +100,7 @@ static constexpr Register WasmTlsReg{Registers::invalid_reg};
+ static constexpr Register WasmJitEntryReturnScratch{Registers::invalid_reg};
+ 
+ static constexpr uint32_t ABIStackAlignment = 4;
+-static constexpr uint32_t CodeAlignment = sizeof(void*);
++static constexpr uint32_t CodeAlignment = 8;
+ static constexpr uint32_t JitStackAlignment = 8;
+ static constexpr uint32_t JitStackValueAlignment =
+     JitStackAlignment / sizeof(Value);