diff --git a/lib/axmap.c b/lib/axmap.c
index 15cd635..5b8cb30 100644
--- a/lib/axmap.c
+++ b/lib/axmap.c
@@ -33,7 +33,7 @@
 #error "Number of arch bits unknown"
 #endif
 
-#define BLOCKS_PER_UNIT		(1UL << UNIT_SHIFT)
+#define BLOCKS_PER_UNIT		(1U << UNIT_SHIFT)
 #define BLOCKS_PER_UNIT_MASK	(BLOCKS_PER_UNIT - 1)
 
 #define firstfree_valid(b)	((b)->first_free != (uint64_t) -1)
diff --git a/lib/zipf.c b/lib/zipf.c
index 9b6ce63..e75dc2a 100644
--- a/lib/zipf.c
+++ b/lib/zipf.c
@@ -11,7 +11,7 @@
 #include "../minmax.h"
 #include "../hash.h"
 
-#define ZIPF_MAX_GEN	10000000
+#define ZIPF_MAX_GEN	10000000UL
 
 static void zipf_update(struct zipf_state *zs)
 {
diff --git a/parse.c b/parse.c
index e6d9406..40cd465 100644
--- a/parse.c
+++ b/parse.c
@@ -380,7 +380,7 @@
 	return 1;
 }
 
-static int opt_len(const char *str)
+static size_t opt_len(const char *str)
 {
 	char *postfix;