diff --git a/src/llvm_backend.hpp b/src/llvm_backend.hpp
index 884b87998..e10471527 100644
--- a/src/llvm_backend.hpp
+++ b/src/llvm_backend.hpp
@@ -726,6 +726,8 @@ lbCallingConventionKind const lb_calling_convention_map[ProcCC_MAX] = {
 	lbCallingConvention_X86_64_SysV,  // ProcCC_SysV,
 
 	lbCallingConvention_PreserveNone,  // ProcCC_PreserveNone,
+	lbCallingConvention_PreserveMost,  // ProcCC_PreserveMost,
+	lbCallingConvention_PreserveAll,   // ProcCC_PreserveAll,
 
 };
 
diff --git a/src/parser.cpp b/src/parser.cpp
index 8782b3a2b..fc55dae97 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -4022,6 +4022,8 @@ gb_internal ProcCallingConvention string_to_calling_convention(String const &s)
 	if (s == "sysv")        return ProcCC_SysV;
 
 	if (s == "preserve/none") return ProcCC_PreserveNone;
+	if (s == "preserve/most") return ProcCC_PreserveMost;
+	if (s == "preserve/all")  return ProcCC_PreserveAll;
 
 	if (s == "system") {
 		if (build_context.metrics.os == TargetOs_windows) {
diff --git a/src/parser.hpp b/src/parser.hpp
index 77d38b291..011330438 100644
--- a/src/parser.hpp
+++ b/src/parser.hpp
@@ -302,6 +302,8 @@ enum ProcCallingConvention : i32 {
 	ProcCC_SysV        = 10,
 
 	ProcCC_PreserveNone = 11,
+	ProcCC_PreserveMost = 12,
+	ProcCC_PreserveAll  = 13,
 
 	ProcCC_MAX,
 
@@ -322,6 +324,8 @@ gb_global char const *proc_calling_convention_strings[ProcCC_MAX] = {
 	"win64",
 	"sysv",
 	"preserve/none",
+	"preserve/most",
+	"preserve/all",
 };
 
 gb_internal ProcCallingConvention default_calling_convention(void) {