diff --git a/compileopts/target.go b/compileopts/target.go
index ba5f7382..19951426 100644
--- a/compileopts/target.go
+++ b/compileopts/target.go
@@ -253,6 +253,9 @@ func defaultTarget(goos, goarch, triple string) (*TargetSpec, error) {
 		GDB:              []string{"gdb"},
 		PortReset:        "false",
 	}
+	if goarch == "386" {
+		spec.CPU = "pentium4"
+	}
 	if goos == "darwin" {
 		spec.CFlags = append(spec.CFlags, "-isysroot", "/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk")
 		spec.LDFlags = append(spec.LDFlags, "-Wl,-dead_strip")
diff --git a/src/internal/task/task_stack_386.go b/src/internal/task/task_stack_386.go
index 3f1cd3ee..c0f06659 100644
--- a/src/internal/task/task_stack_386.go
+++ b/src/internal/task/task_stack_386.go
@@ -16,6 +16,9 @@ type calleeSavedRegs struct {
 	ebp uintptr
 
 	pc uintptr
+
+	// Pad this struct so that tasks start on a 16-byte aligned stack.
+	_ [3]uintptr
 }
 
 // archInit runs architecture-specific setup for the goroutine startup.
diff --git a/src/runtime/arch_386.go b/src/runtime/arch_386.go
index 2dd7c9ff..9f1a99c0 100644
--- a/src/runtime/arch_386.go
+++ b/src/runtime/arch_386.go
@@ -9,7 +9,7 @@ const TargetBits = 32
 
 // Align on word boundary.
 func align(ptr uintptr) uintptr {
-	return (ptr + 3) &^ 3
+	return (ptr + 15) &^ 15
 }
 
 func getCurrentStackPointer() uintptr {
diff --git a/src/runtime/gc_386.S b/src/runtime/gc_386.S
index 3ca80151..9604ddbd 100644
--- a/src/runtime/gc_386.S
+++ b/src/runtime/gc_386.S
@@ -13,10 +13,11 @@ tinygo_scanCurrentStack:
     pushl %ebp
 
     // Scan the stack.
+    subl $8, %esp // adjust the stack before the call to maintain 16-byte alignment
     pushl %esp
     calll tinygo_scanstack
 
     // Restore the stack pointer. Registers do not need to be restored as they
     // were only pushed to be discoverable by the GC.
-    addl $20, %esp
+    addl $28, %esp
     retl
diff --git a/src/runtime/math.go b/src/runtime/math.go
index 5498da6f..f1617385 100644
--- a/src/runtime/math.go
+++ b/src/runtime/math.go
@@ -217,7 +217,7 @@ func math_sinh(x float64) float64
 
 //go:linkname math_Sqrt math.Sqrt
 func math_Sqrt(x float64) float64 {
-	if GOARCH == "x86" || GOARCH == "amd64" || GOARCH == "wasm" {
+	if GOARCH == "386" || GOARCH == "amd64" || GOARCH == "wasm" {
 		return llvm_sqrt(x)
 	}
 	return math_sqrt(x)