diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7d86e9c..b8fc18a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,7 +9,7 @@ project("hdr_histogram")
 ENABLE_TESTING()
 
 if(UNIX)
-    set(CMAKE_C_FLAGS "-Wall -Wno-unknown-pragmas -Wextra -Wshadow -Winit-self")
+    set(CMAKE_C_FLAGS "-Wall -Wno-unknown-pragmas -Wextra -Wshadow -Winit-self -Wmissing-prototypes")
     set(CMAKE_C_FLAGS_DEBUG "-O0 -g")
     set(CMAKE_C_FLAGS_RELEASE "-O3 -g")
 endif()
diff --git a/examples/hiccup.c b/examples/hiccup.c
index 4e4d247..c606c9c 100644
--- a/examples/hiccup.c
+++ b/examples/hiccup.c
@@ -23,7 +23,7 @@
 #include <hdr_interval_recorder.h>
 #include <hdr_time.h>
 
-int64_t diff(struct timespec t0, struct timespec t1)
+static int64_t diff(struct timespec t0, struct timespec t1)
 {
     int64_t delta_us = 0;
     delta_us = (t1.tv_sec - t0.tv_sec) * 1000000;
@@ -32,7 +32,7 @@ int64_t diff(struct timespec t0, struct timespec t1)
     return delta_us;
 }
 
-void update_histogram(void* data, void* arg)
+static void update_histogram(void* data, void* arg)
 {
     struct hdr_histogram* h = data;
     int64_t* values = arg;
@@ -40,7 +40,7 @@ void update_histogram(void* data, void* arg)
     hdr_record_value(h, values[0]);
 }
 
-void* record_hiccups(void* thread_context)
+static void* record_hiccups(void* thread_context)
 {
     struct pollfd fd;
     struct timespec t0;
@@ -90,7 +90,7 @@ const char* USAGE =
 "  interval: <number> Time in seconds between samples (default 1).\n"
 "  filename: <string> Name of the file to log to (default stdout).\n";
 
-int handle_opts(int argc, char** argv, struct config_t* config)
+static int handle_opts(int argc, char** argv, struct config_t* config)
 {
     int c;
     int interval = 1;
@@ -205,4 +205,4 @@ int main(int argc, char** argv)
 #pragma clang diagnostic pop
 
     pthread_exit(NULL);
-}
\ No newline at end of file
+}
diff --git a/src/hdr_encoding.c b/src/hdr_encoding.c
index 5d8e16d..7291290 100644
--- a/src/hdr_encoding.c
+++ b/src/hdr_encoding.c
@@ -7,6 +7,7 @@
 #include <math.h>
 
 #include "hdr_encoding.h"
+#include "hdr_tests.h"
 
 int zig_zag_encode_i64(uint8_t* buffer, int64_t signed_value)
 {
@@ -207,7 +208,7 @@ size_t hdr_base64_decoded_len(size_t encoded_size)
     return (encoded_size / 4) * 3;
 }
 
-void hdr_base64_encode_block_pad(const uint8_t* input, char* output, size_t pad)
+static void hdr_base64_encode_block_pad(const uint8_t* input, char* output, size_t pad)
 {
     uint32_t _24_bit_value = 0;
 
diff --git a/src/hdr_histogram.c b/src/hdr_histogram.c
index d1e8bb5..6b67634 100644
--- a/src/hdr_histogram.c
+++ b/src/hdr_histogram.c
@@ -15,6 +15,7 @@
 #include <inttypes.h>
 
 #include "hdr_histogram.h"
+#include "hdr_tests.h"
 
 //  ######   #######  ##     ## ##    ## ########  ######  
 // ##    ## ##     ## ##     ## ###   ##    ##    ##    ## 
@@ -220,7 +221,7 @@ void hdr_reset_internal_counters(struct hdr_histogram* h)
     h->total_count = observed_total_count;
 }
 
-int32_t buckets_needed_to_cover_value(int64_t value, int32_t sub_bucket_count, int32_t unit_magnitude)
+static int32_t buckets_needed_to_cover_value(int64_t value, int32_t sub_bucket_count, int32_t unit_magnitude)
 {
     int64_t smallest_untrackable_value = ((int64_t) sub_bucket_count) << unit_magnitude;
     int32_t buckets_needed = 1;
@@ -686,7 +687,7 @@ bool hdr_iter_next(struct hdr_iter* iter)
 // ##        ##       ##    ##  ##    ## ##       ##   ###    ##     ##  ##       ##       ##    ##
 // ##        ######## ##     ##  ######  ######## ##    ##    ##    #### ######## ########  ######
 
-bool _percentile_iter_next(struct hdr_iter* iter)
+static bool _percentile_iter_next(struct hdr_iter* iter)
 {
     struct hdr_iter_percentiles* percentiles = &iter->specifics.percentiles;
 
@@ -772,7 +773,7 @@ static void format_line_string(char* str, size_t len, int significant_figures, f
 // ##     ## ########  ######   #######  ##     ## ########  ######## ########
 
 
-bool _recorded_iter_next(struct hdr_iter* iter)
+static bool _recorded_iter_next(struct hdr_iter* iter)
 {
     while (_basic_iter_next(iter))
     {
@@ -806,7 +807,7 @@ void hdr_iter_recorded_init(struct hdr_iter* iter, const struct hdr_histogram* h
 // ######## #### ##    ## ######## ##     ## ##     ##
 
 
-bool _iter_linear_next(struct hdr_iter* iter)
+static bool _iter_linear_next(struct hdr_iter* iter)
 {
     struct hdr_iter_linear* linear = &iter->specifics.linear;
 
@@ -862,7 +863,7 @@ void hdr_iter_linear_init(struct hdr_iter* iter, const struct hdr_histogram* h,
 // ##       ##     ## ##    ##  ##     ## ##    ##   ##     ##    ##     ## ##     ##  ##  ##    ##
 // ########  #######   ######   ##     ## ##     ## ####    ##    ##     ## ##     ## ####  ######
 
-bool _log_iter_next(struct hdr_iter *iter)
+static bool _log_iter_next(struct hdr_iter *iter)
 {
     struct hdr_iter_log* logarithmic = &iter->specifics.log;
 
diff --git a/src/hdr_histogram_log.c b/src/hdr_histogram_log.c
index e0d77a7..314fd22 100644
--- a/src/hdr_histogram_log.c
+++ b/src/hdr_histogram_log.c
@@ -20,6 +20,7 @@
 #include "hdr_encoding.h"
 #include "hdr_histogram.h"
 #include "hdr_histogram_log.h"
+#include "hdr_tests.h"
 
 #ifdef __APPLE__
 
@@ -54,7 +55,7 @@ int32_t counts_index_for(const struct hdr_histogram* h, int64_t value);
     }                       \
     while (0)
 
-int realloc_buffer(
+static int realloc_buffer(
     void** buffer, size_t nmemb, ssize_t size)
 {
     size_t len = nmemb * size;
@@ -86,7 +87,7 @@ int realloc_buffer(
 // ##    ##    ##    ##    ##   ##  ##   ### ##    ##  ##    ##
 //  ######     ##    ##     ## #### ##    ##  ######    ######
 
-ssize_t null_trailing_whitespace(char* s, ssize_t len)
+static ssize_t null_trailing_whitespace(char* s, ssize_t len)
 {
     ssize_t i = len;
     while (--i != -1)
@@ -121,12 +122,12 @@ static const int32_t V1_COMPRESSION_COOKIE = 0x1c849302;
 static const int32_t V2_ENCODING_COOKIE = 0x1c849303;
 static const int32_t V2_COMPRESSION_COOKIE = 0x1c849304;
 
-int32_t get_cookie_base(int32_t cookie)
+static int32_t get_cookie_base(int32_t cookie)
 {
     return (cookie & ~0xf0);
 }
 
-int32_t word_size_from_cookie(int32_t cookie)
+static int32_t word_size_from_cookie(int32_t cookie)
 {
     return (cookie & 0xf0) >> 4;
 }
diff --git a/src/hdr_writer_reader_phaser.c b/src/hdr_writer_reader_phaser.c
index e926a1a..ea1b724 100644
--- a/src/hdr_writer_reader_phaser.c
+++ b/src/hdr_writer_reader_phaser.c
@@ -14,17 +14,17 @@
 
 #include "hdr_writer_reader_phaser.h"
 
-int64_t _hdr_phaser_get_epoch(int64_t* field)
+static int64_t _hdr_phaser_get_epoch(int64_t* field)
 {
     return __atomic_load_n(field, __ATOMIC_SEQ_CST);
 }
 
-void _hdr_phaser_set_epoch(int64_t* field, int64_t val)
+static void _hdr_phaser_set_epoch(int64_t* field, int64_t val)
 {
     __atomic_store_n(field, val, __ATOMIC_SEQ_CST);
 }
 
-int64_t _hdr_phaser_reset_epoch(int64_t* field, int64_t initial_value)
+static int64_t _hdr_phaser_reset_epoch(int64_t* field, int64_t initial_value)
 {
     return __atomic_exchange_n(field, initial_value, __ATOMIC_SEQ_CST);
 }
diff --git a/test/hdr_histogram_log_test.c b/test/hdr_histogram_log_test.c
index 13b331f..79a4040 100644
--- a/test/hdr_histogram_log_test.c
+++ b/test/hdr_histogram_log_test.c
@@ -818,7 +818,7 @@ static struct mu_result all_tests()
     mu_ok;
 }
 
-int hdr_histogram_log_run_tests()
+static int hdr_histogram_log_run_tests()
 {
     struct mu_result result = all_tests();
 
diff --git a/test/hdr_histogram_perf.c b/test/hdr_histogram_perf.c
index 9fb3ce3..61c5aea 100644
--- a/test/hdr_histogram_perf.c
+++ b/test/hdr_histogram_perf.c
@@ -13,7 +13,7 @@
 
 #include "hdr_time.h"
 
-struct timespec diff(struct timespec start, struct timespec end)
+static struct timespec diff(struct timespec start, struct timespec end)
 {
     struct timespec temp;
     if ((end.tv_nsec-start.tv_nsec) < 0)
@@ -29,12 +29,6 @@ struct timespec diff(struct timespec start, struct timespec end)
     return temp;
 }
 
-void inc(struct hdr_histogram* h, int32_t index, int64_t value)
-{
-    h->counts[index] += value;
-    h->total_count += value;
-}
-
 int main()
 {
     struct hdr_histogram* histogram;
diff --git a/test/hdr_histogram_test.c b/test/hdr_histogram_test.c
index ef21349..c1ed2d6 100644
--- a/test/hdr_histogram_test.c
+++ b/test/hdr_histogram_test.c
@@ -14,12 +14,12 @@
 
 #include "minunit.h"
 
-bool compare_values(double a, double b, double variation)
+static bool compare_values(double a, double b, double variation)
 {
     return compare_double(a, b, b * variation);
 }
 
-bool compare_percentile(int64_t a, double b, double variation)
+static bool compare_percentile(int64_t a, double b, double variation)
 {
     return compare_values((double) a, b, variation);
     // return fabs(a - b) <= b * variation;
@@ -425,7 +425,7 @@ static char* test_scaling_equivalence()
     return 0;
 }
 
-char* test_out_of_range_values()
+static char* test_out_of_range_values()
 {
     struct hdr_histogram *h;
     hdr_init(1, 1000, 4, &h);
@@ -455,7 +455,7 @@ static struct mu_result all_tests()
     mu_ok;
 }
 
-int hdr_histogram_run_tests()
+static int hdr_histogram_run_tests()
 {
     struct mu_result result = all_tests();
 
diff --git a/test/minunit.h b/test/minunit.h
index 6c4c847..fe289dc 100644
--- a/test/minunit.h
+++ b/test/minunit.h
@@ -44,7 +44,7 @@ struct mu_result
 
 extern int tests_run;
 
-bool compare_double(double a, double b, double delta)
+static bool compare_double(double a, double b, double delta)
 {
     if (fabs(a - b) < delta)
     {
@@ -66,4 +66,4 @@ static bool compare_int64(int64_t a, int64_t b)
     return false;
 }
 
-#endif
\ No newline at end of file
+#endif