diff --git a/src/asm/lexer.c b/src/asm/lexer.c
index aacdb938..89c52880 100644
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -257,6 +257,7 @@ struct LexerState {
 			char *ptr; /* Technically `const` during the lexer's execution */
 			off_t size;
 			off_t offset;
+			bool isReferenced; /* If a macro in this file requires not unmapping it*/
 		};
 		struct { /* Otherwise */
 			int fd;
@@ -415,7 +416,7 @@ void lexer_DeleteState(struct LexerState *state)
 {
 	if (!state->isMmapped)
 		close(state->fd);
-	else if (state->isFile)
+	else if (state->isFile && !state->isReferenced)
 		munmap(state->ptr, state->size);
 	free(state);
 }
@@ -1944,6 +1945,11 @@ void lexer_CaptureMacroBody(char **capture, size_t *size)
 	unsigned int level = 0;
 	int c = peek(0);
 
+	/* If the file is `mmap`ed, we need not to unmap it to keep access to the macro */
+	if (lexerState->isMmapped)
+		/* FIXME: this is godawful, but RGBASM doesn't even clean up anything anyways. */
+		lexerState->isReferenced = true;
+
 	/*
 	 * Due to parser internals, it does not read the EOL after the T_POP_MACRO before calling
 	 * this. Thus, we need to keep one in the buffer afterwards.