diff --git a/core/mem/virtual/virtual_darwin.odin b/core/mem/virtual/virtual_darwin.odin
index ac952494a..63f7f0771 100644
--- a/core/mem/virtual/virtual_darwin.odin
+++ b/core/mem/virtual/virtual_darwin.odin
@@ -2,7 +2,7 @@ package mem_virtual
 
 import "core:sys/posix"
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 	result := posix.mmap(rawptr(address_hint), size, {}, {.ANONYMOUS, .PRIVATE})
 	if result == posix.MAP_FAILED {
 		assert_contextless(posix.errno() == .ENOMEM)
diff --git a/core/mem/virtual/virtual_freebsd.odin b/core/mem/virtual/virtual_freebsd.odin
index 00b5b6e6a..d055d6052 100644
--- a/core/mem/virtual/virtual_freebsd.odin
+++ b/core/mem/virtual/virtual_freebsd.odin
@@ -2,7 +2,7 @@ package mem_virtual
 
 import "core:sys/posix"
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 
 	PROT_MAX :: proc "contextless" (flags: posix.Prot_Flags) -> posix.Prot_Flags {
 		_PROT_MAX_SHIFT :: 16
diff --git a/core/mem/virtual/virtual_linux.odin b/core/mem/virtual/virtual_linux.odin
index 380f2f8f7..92f55c4a3 100644
--- a/core/mem/virtual/virtual_linux.odin
+++ b/core/mem/virtual/virtual_linux.odin
@@ -4,7 +4,7 @@ package mem_virtual
 
 import "core:sys/linux"
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 	addr, errno := linux.mmap(address_hint, size, {}, {.PRIVATE, .ANONYMOUS})
 	if errno == .ENOMEM {
 		return nil, .Out_Of_Memory
diff --git a/core/mem/virtual/virtual_netbsd.odin b/core/mem/virtual/virtual_netbsd.odin
index ef5de1b82..afd2e27f4 100644
--- a/core/mem/virtual/virtual_netbsd.odin
+++ b/core/mem/virtual/virtual_netbsd.odin
@@ -2,7 +2,7 @@ package mem_virtual
 
 import "core:sys/posix"
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 
 	PROT_MPROTECT :: proc "contextless" (flags: posix.Prot_Flags) -> posix.Prot_Flags {
 		return transmute(posix.Prot_Flags)(transmute(i32)flags << 3)
diff --git a/core/mem/virtual/virtual_openbsd.odin b/core/mem/virtual/virtual_openbsd.odin
index 3669c05da..41adf359c 100644
--- a/core/mem/virtual/virtual_openbsd.odin
+++ b/core/mem/virtual/virtual_openbsd.odin
@@ -2,7 +2,7 @@ package mem_virtual
 
 import "core:sys/posix"
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 	result := posix.mmap(rawptr(address_hint), size, {}, {.ANONYMOUS, .PRIVATE})
 	if result == posix.MAP_FAILED {
 		assert_contextless(posix.errno() == .ENOMEM)
diff --git a/core/mem/virtual/virtual_other.odin b/core/mem/virtual/virtual_other.odin
index 1f562cc8e..6f9c1327a 100644
--- a/core/mem/virtual/virtual_other.odin
+++ b/core/mem/virtual/virtual_other.odin
@@ -7,7 +7,7 @@
 #+build !windows
 package mem_virtual
 
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 	return nil, nil
 }
 
diff --git a/core/mem/virtual/virtual_windows.odin b/core/mem/virtual/virtual_windows.odin
index 9c2565dd6..14fc35f62 100644
--- a/core/mem/virtual/virtual_windows.odin
+++ b/core/mem/virtual/virtual_windows.odin
@@ -87,7 +87,7 @@ foreign Kernel32 {
 }
 
 @(no_sanitize_address)
-_reserve :: proc "contextless" (size: uint, address_hint := uintptr(0)) -> (data: []byte, err: Allocator_Error) {
+_reserve :: proc "contextless" (size: uint, address_hint: uintptr) -> (data: []byte, err: Allocator_Error) {
 	result := VirtualAlloc(rawptr(address_hint), size, MEM_RESERVE, PAGE_READWRITE)
 	if result == nil {
 		err = .Out_Of_Memory