diff --git a/crc16speed.h b/crc16speed.h
index 49db646..ffcbb1b 100644
--- a/crc16speed.h
+++ b/crc16speed.h
@@ -1,5 +1,10 @@
 #ifndef CRC16SPEED_H
 #define CRC16SPEED_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 #include "crcspeed.h"
 #include "stdbool.h"
 
@@ -17,4 +22,9 @@ uint16_t crc16speed_big(uint16_t crc, const void *s, const uint64_t l);
 
 bool crc16speed_init_native(void);
 uint16_t crc16speed_native(uint16_t crc, const void *s, const uint64_t l);
+
+#if defined(__cplusplus)
+}
+#endif
+
 #endif
diff --git a/crc64speed.h b/crc64speed.h
index c72cd8f..586d8ef 100644
--- a/crc64speed.h
+++ b/crc64speed.h
@@ -1,5 +1,10 @@
 #ifndef CRC64SPEED_H
 #define CRC64SPEED_H
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 #include "crcspeed.h"
 #include "stdbool.h"
 
@@ -17,4 +22,9 @@ uint64_t crc64speed_big(uint64_t crc, const void *s, const uint64_t l);
 
 bool crc64speed_init_native(void);
 uint64_t crc64speed_native(uint64_t crc, const void *s, const uint64_t l);
+
+#if defined(__cplusplus)
+}
+#endif
+
 #endif
diff --git a/crc_simd.h b/crc_simd.h
index 629497d..0d6fad2 100644
--- a/crc_simd.h
+++ b/crc_simd.h
@@ -10,6 +10,10 @@
 #ifndef CRC_SIMD_H
 #define CRC_SIMD_H
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -25,4 +29,8 @@ uint64_t crc64_simd(uint64_t crc, const void *data, uint64_t len);
 void crc16_simd_init(void);
 uint16_t crc16_simd(uint16_t crc, const void *data, uint64_t len);
 
+#if defined(__cplusplus)
+}
+#endif
+
 #endif /* CRC_SIMD_H */
diff --git a/crcspeed.h b/crcspeed.h
index d7ee95e..71af1b9 100644
--- a/crcspeed.h
+++ b/crcspeed.h
@@ -28,6 +28,10 @@
 #ifndef CRCSPEED_H
 #define CRCSPEED_H
 
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
 #include <inttypes.h>
 #include <stdio.h>
 
@@ -57,4 +61,9 @@ uint16_t crcspeed16big(uint16_t table[8][256], uint16_t crc, void *buf,
                        size_t len);
 uint16_t crcspeed16native(uint16_t table[8][256], uint16_t crc, void *buf,
                           size_t len);
+
+#if defined(__cplusplus)
+}
+#endif
+
 #endif