diff --git a/lib/prime.c b/lib/prime.c
index fc54d34..7560686 100644
--- a/lib/prime.c
+++ b/lib/prime.c
@@ -6,6 +6,8 @@ int is_prime(uint32_t p) {
 
     uint32_t i, l;
 
+    if (p == 2)
+        return 1;
     if (p < 2 || (p & 1) == 0)
         return 0;
 
diff --git a/lib/prime.h b/lib/prime.h
index 2a5a814..aab1600 100644
--- a/lib/prime.h
+++ b/lib/prime.h
@@ -1,6 +1,5 @@
 
 #ifndef __PRIME_H
-
 #define __PRIME_H
 
 #include <stdint.h>