diff --git a/src/magic.c b/src/magic.c
--- a/src/magic.c
+++ b/src/magic.c
@@ -60,6 +60,10 @@
 #include <unistd.h>	/* for read() */
 #endif
 
+#ifdef __APPLE__
+#include <mach-o/dyld.h>
+#endif
+
 #ifndef PIPE_BUF
 /* Get the PIPE_BUF from pathconf */
 #ifdef _PC_PIPE_BUF
@@ -184,7 +188,47 @@
 	if (default_magic) {
 		free(default_magic);
 		default_magic = NULL;
+	}
+
+	// Limited runfiles lookup bootstrap.
+	char exe_path[PATH_MAX];
+#ifdef __linux__
+	ssize_t len = readlink("/proc/self/exe", exe_path, sizeof(exe_path)-1);
+	if (len < 0) {
+		return MAGIC;
+	}
+	exe_path[len] = '\0';
+#elif defined(__APPLE__)
+	uint32_t size = sizeof(exe_path);
+	if (_NSGetExecutablePath(exe_path, &size) != 0) {
+		return MAGIC;
+	}
+#endif
+
+	// Build runfiles path and make sure it exists.
+	if (asprintf(&default_magic, "%s.runfiles/%s", exe_path, MAGIC) >= 0 && access(default_magic, R_OK) == 0) {
+		return default_magic;
 	}
+
+	default_magic = NULL;
+
+	// Fallback: check for magic.mgc in same directory as exe (sibling in runfiles)
+	char *exe_copy = strdup(exe_path);
+	if (exe_copy) {
+		char *last_slash = strrchr(exe_copy, '/');
+		if (last_slash) {
+			*last_slash = '\0';
+			if (asprintf(&default_magic, "%s/magic.mgc", exe_copy) >= 0 &&
+			    access(default_magic, R_OK) == 0) {
+				free(exe_copy);
+				return default_magic;
+			}
+			free(default_magic);
+			default_magic = NULL;
+		}
+		free(exe_copy);
+	}
+
 	if ((home = getenv("HOME")) == NULL)
 		return MAGIC;