diff --git a/core/rec-ARM/rec_arm.cpp b/core/rec-ARM/rec_arm.cpp
index edd80b625..c8eb112aa 100644
--- a/core/rec-ARM/rec_arm.cpp
+++ b/core/rec-ARM/rec_arm.cpp
@@ -778,6 +778,9 @@ bool Arm32Dynarec::rewrite(host_context_t& context, void *faultAddress)
 		u32 full;
 	};
 
+	if (codeBuffer == nullptr)
+		// init() not called yet
+		return false;
 	if ((u8 *)context.pc < (u8 *)codeBuffer->getBase()
 			|| (u8 *)context.pc >= (u8 *)codeBuffer->getBase() + codeBuffer->getSize())
 		return false;
diff --git a/core/rec-ARM64/rec_arm64.cpp b/core/rec-ARM64/rec_arm64.cpp
index 04d56151a..260adfbd1 100644
--- a/core/rec-ARM64/rec_arm64.cpp
+++ b/core/rec-ARM64/rec_arm64.cpp
@@ -2312,6 +2312,9 @@ public:
 				8,
 		};
 
+		if (codeBuffer == nullptr)
+			// init() not called yet
+			return false;
 		//LOGI("Sh4Dynarec::rewrite pc %zx\n", context.pc);
 		u32 *code_ptr = (u32 *)CC_RX2RW(context.pc);
 		if ((u8 *)code_ptr < (u8 *)codeBuffer->getBase()
@@ -2355,7 +2358,7 @@ public:
 private:
 	Arm64Assembler* compiler = nullptr;
 	bool restarting = false;
-	Sh4CodeBuffer *codeBuffer;
+	Sh4CodeBuffer *codeBuffer = nullptr;
 };
 
 static Arm64Dynarec instance;
diff --git a/core/rec-x64/rec_x64.cpp b/core/rec-x64/rec_x64.cpp
index 817c0aff8..db2f7fe5f 100644
--- a/core/rec-x64/rec_x64.cpp
+++ b/core/rec-x64/rec_x64.cpp
@@ -1360,6 +1360,9 @@ public:
 
 	bool rewrite(host_context_t &context, void *faultAddress) override
 	{
+		if (codeBuffer == nullptr)
+			// init() not called yet
+			return false;
 		void* protStart = codeBuffer->get();
 		size_t protSize = codeBuffer->getFreeSpace();
 		virtmem::jit_set_exec(protStart, protSize, false);
diff --git a/core/rec-x86/rec_x86.cpp b/core/rec-x86/rec_x86.cpp
index e742ebfc1..54188fe16 100644
--- a/core/rec-x86/rec_x86.cpp
+++ b/core/rec-x86/rec_x86.cpp
@@ -924,6 +924,9 @@ public:
 
 	bool rewrite(host_context_t &context, void *faultAddress) override
 	{
+		if (codeBuffer == nullptr)
+			// init() not called yet
+			return false;
 		u8 *rewriteAddr = *(u8 **)context.esp - 5;
 		X86Compiler *compiler = new X86Compiler(*codeBuffer, rewriteAddr);
 		bool rv = compiler->rewriteMemAccess(context);